- GE Digital Energy

GE Consumer & Industrial
Multilin
745 Transformer Protection
System
Instruction Manual
745 revision: 5.11
Manual Part Number: 1601-0161-A7
GE publication code: GEK-106635F
Copyright © 2009 GE Multilin
Canada L6E 1B3
Tel: (905) 294-6222 Fax: (905) 201-2098
Internet: http://www.GEmultilin.com
*1601-0161-A7*
RE
ISO9001:2000
I
N
EM
G
215 Anderson Avenue, Markham, Ontario
T
GIS ERE
D
GE Multilin
U LT I L
GE Multilin's Quality
Management System is
registered to ISO9001:2000
QMI # 005094
UL # A3775
© 2008 GE Multilin Incorporated. All rights reserved.
GE Multilin 745 Transformer Protection System instruction manual for revision 5.11.
745 Transformer Protection System, EnerVista, EnerVista Launchpad, EnerVista 745 Setup, and FlexLogic are registered
trademarks of GE Multilin Inc.
The contents of this manual are the property of GE Multilin Inc. This documentation is furnished on license and may not be
reproduced in whole or in part without the permission of GE Multilin. The content of this manual is for informational use
only and is subject to change without notice.
Part numbers contained in this manual are subject to change without notice, and should therefore be verified by GE
Multilin before ordering.
Part number: 1601-0161-A7 (June 2009)
GE Consumer & Industrial
Multilin
745 TRANSFORMER
PROTECTION SYSTEM
Table of contents
1:GETTING STARTED
Important Procedures ...............................................................................................1–1
Cautions and Warnings............................................................................................................................1–1
Inspection Checklist ...................................................................................................................................1–1
Manual Organization .................................................................................................................................1–2
Using the Relay ...........................................................................................................1–3
Menu Navigation .........................................................................................................................................1–3
Panel Keying Example...............................................................................................................................1–5
Changing Setpoints....................................................................................................1–6
Introduction ...................................................................................................................................................1–6
Using the HELP Key ....................................................................................................................................1–6
Numerical Setpoints...................................................................................................................................1–6
Enumeration Setpoints .............................................................................................................................1–7
Text Setpoints................................................................................................................................................1–7
Security ........................................................................................................................1–9
Installation ......................................................................................................................................................1–9
Changing the Passcode ...........................................................................................................................1–9
Disabling and Enabling Passcode Security ..................................................................................1–10
2:OVERVIEW
Introduction.................................................................................................................2–1
Description .....................................................................................................................................................2–1
Protection Features....................................................................................................................................2–2
Order Codes ...................................................................................................................................................2–3
Specifications ..............................................................................................................2–5
Applicability....................................................................................................................................................2–5
Inputs ................................................................................................................................................................2–5
Protection Elements ...................................................................................................................................2–6
Outputs.............................................................................................................................................................2–9
Miscellaneous.............................................................................................................................................2–10
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
0–i
TABLE OF CONTENTS
3:INSTALLATION
Drawout Case..............................................................................................................3–1
Case Description ......................................................................................................................................... 3–1
Panel Cutout.................................................................................................................................................. 3–2
Case Mounting ............................................................................................................................................. 3–2
Unit Withdrawal and Insertion ............................................................................................................. 3–3
Ethernet connection .................................................................................................................................. 3–6
Typical Wiring .............................................................................................................3–7
Description ..................................................................................................................................................... 3–7
Rear Terminal Layout................................................................................................................................ 3–7
Wiring Diagrams ...................................................................................................................................... 3–10
Phase Sequence and Transformer Polarity ................................................................................. 3–12
Current Transformer Inputs ................................................................................................................ 3–12
AC Voltage Input....................................................................................................................................... 3–14
Logic Inputs ................................................................................................................................................ 3–14
Control Power ............................................................................................................................................ 3–15
Analog Input ............................................................................................................................................... 3–16
Tap Position Input .................................................................................................................................... 3–16
RTD Driver/Sensor.................................................................................................................................... 3–16
Output Relays ............................................................................................................................................ 3–16
Solid State Trip Output........................................................................................................................... 3–17
Analog Outputs ......................................................................................................................................... 3–17
RS485/RS422 Communications ........................................................................................................ 3–17
RS232 Front Panel Program Port...................................................................................................... 3–19
IRIG-B............................................................................................................................................................. 3–20
Dielectric Strength................................................................................................................................... 3–20
4:INTERFACES
Hardware Interface....................................................................................................4–1
Front Panel..................................................................................................................................................... 4–1
Display.............................................................................................................................................................. 4–2
LEDs................................................................................................................................................................... 4–2
LED Indicators............................................................................................................................................... 4–2
Program Port................................................................................................................................................. 4–4
Keypad ............................................................................................................................................................. 4–4
Setpoint Entry ............................................................................................................................................... 4–5
Diagnostic Messages ................................................................................................................................ 4–7
Flash Messages............................................................................................................................................ 4–7
EnerVista Software Interface ...................................................................................4–8
Overview ......................................................................................................................................................... 4–8
Hardware........................................................................................................................................................ 4–8
Installing the EnerVista 745 Setup Software............................................................................... 4–10
Connecting EnerVista 745 Setup to the relay..................................................... 4–13
Configuring serial communications ................................................................................................ 4–13
Using the Quick Connect Feature .................................................................................................... 4–15
Configuring Ethernet communications ......................................................................................... 4–15
Connecting to the Relay ....................................................................................................................... 4–17
Working with Setpoints and Setpoint Files......................................................... 4–19
Engaging a Device................................................................................................................................... 4–19
Entering Setpoints ................................................................................................................................... 4–19
File Support................................................................................................................................................. 4–21
Using Setpoints Files............................................................................................................................... 4–21
Upgrading Relay Firmware.................................................................................... 4–27
0–II
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
TABLE OF CONTENTS
Description ..................................................................................................................................................4–27
Saving Setpoints to a File......................................................................................................................4–27
Loading New Firmware .........................................................................................................................4–27
Advanced EnerVista 745 Setup Features ............................................................ 4–30
Triggered Events .......................................................................................................................................4–30
Waveform Capture (trace memory).................................................................................................4–30
Trending (data logger)............................................................................................................................4–32
Event Recorder ..........................................................................................................................................4–35
Modbus User Map ....................................................................................................................................4–36
Viewing Actual Values............................................................................................................................4–37
Using EnerVista Viewpoint with the 745 ............................................................. 4–40
Plug and Play Example ..........................................................................................................................4–40
5:SETPOINTS
Overview ......................................................................................................................5–1
Setpoint Message Map .............................................................................................................................5–1
Setpoint entry................................................................................................................................................5–4
Setpoint Write Access ...............................................................................................................................5–4
Auto-configuration ....................................................................................................5–6
Introduction ...................................................................................................................................................5–6
Dynamic CT Ratio Mismatch Correction...........................................................................................5–6
Phase Shifts on Three-phase Transformers ...................................................................................5–8
Phase Angle Correction .........................................................................................................................5–10
Zero-sequence Component Removal.............................................................................................5–11
Transformer Types...................................................................................................................................5–13
Phase Shifts.................................................................................................................................................5–24
S1 745 setup ............................................................................................................. 5–25
Passcode ......................................................................................................................................................5–25
Preferences .................................................................................................................................................5–25
Communications ......................................................................................................................................5–26
Resetting.......................................................................................................................................................5–29
Clock ...............................................................................................................................................................5–29
Default Messages.....................................................................................................................................5–30
Scratchpad ..................................................................................................................................................5–31
Installation ...................................................................................................................................................5–31
Upgrade Options ......................................................................................................................................5–31
Setup Event Recorder.............................................................................................................................5–33
S2 System Setup ...................................................................................................... 5–34
Description ..................................................................................................................................................5–34
Transformer ................................................................................................................................................5–34
Windings 1 to 3..........................................................................................................................................5–36
Onload Tap Changer...............................................................................................................................5–37
Harmonics ...................................................................................................................................................5–38
FlexCurves™ ...............................................................................................................................................5–38
Voltage Input ..............................................................................................................................................5–39
Ambient Temperature............................................................................................................................5–39
Analog Input ...............................................................................................................................................5–41
Demand Metering ....................................................................................................................................5–41
Analog Outputs 1 to 7 ............................................................................................................................5–43
S3 Logic Inputs......................................................................................................... 5–44
Description ..................................................................................................................................................5–44
Logic Inputs 1 to 16.................................................................................................................................5–44
Virtual Inputs 1 to 16 ..............................................................................................................................5–45
S4 Elements .............................................................................................................. 5–46
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
0–iii
TABLE OF CONTENTS
Introduction to Elements...................................................................................................................... 5–46
Setpoint Group .......................................................................................................................................... 5–47
Differential Element ................................................................................................................................ 5–48
Instantaneous Differential................................................................................................................... 5–57
Phase Overcurrent .................................................................................................................................. 5–58
Neutral overcurrent ................................................................................................................................ 5–66
Ground Overcurrent ............................................................................................................................... 5–69
Restricted Ground Fault........................................................................................................................ 5–72
Negative Sequence Overcurrent ...................................................................................................... 5–76
Frequency.................................................................................................................................................... 5–78
Overexcitation ........................................................................................................................................... 5–83
Harmonics................................................................................................................................................... 5–88
Insulation Aging........................................................................................................................................ 5–90
Analog Input Level................................................................................................................................... 5–94
Current Demand....................................................................................................................................... 5–95
Transformer Overload ........................................................................................................................... 5–96
Tap Changer Failure ............................................................................................................................... 5–97
S5 Outputs ................................................................................................................ 5–99
Description .................................................................................................................................................. 5–99
Relay Assignments .................................................................................................................................. 5–99
Introduction to FlexLogic™.................................................................................................................. 5–99
FlexLogic™ Rules....................................................................................................................................5–100
Output Relays ..........................................................................................................................................5–102
Trace Memory..........................................................................................................................................5–105
Virtual Outputs ........................................................................................................................................5–106
Timers..........................................................................................................................................................5–106
S6 Testing................................................................................................................ 5–107
Description ................................................................................................................................................5–107
Output Relays ..........................................................................................................................................5–107
Analog Outputs .......................................................................................................................................5–108
Simulation..................................................................................................................................................5–108
Factory Service........................................................................................................................................5–112
6:ACTUAL VALUES
Overview ......................................................................................................................6–1
Message Map................................................................................................................................................ 6–1
Description ..................................................................................................................................................... 6–3
A1 Status ......................................................................................................................6–4
Network Status ............................................................................................................................................ 6–4
Date and Time .............................................................................................................................................. 6–4
Logic Inputs ................................................................................................................................................... 6–4
Virtual Inputs................................................................................................................................................. 6–5
Output Relays ............................................................................................................................................... 6–5
Virtual Outputs ............................................................................................................................................. 6–5
Self-test Errors.............................................................................................................................................. 6–6
A2 Metering .................................................................................................................6–7
Current ............................................................................................................................................................. 6–7
Harmonic Content ................................................................................................................................... 6–10
Frequency.................................................................................................................................................... 6–12
Tap Changer............................................................................................................................................... 6–12
Voltage.......................................................................................................................................................... 6–12
Demand........................................................................................................................................................ 6–13
Ambient Temperature ........................................................................................................................... 6–14
Loss of Life................................................................................................................................................... 6–14
0–IV
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
TABLE OF CONTENTS
Analog Input ...............................................................................................................................................6–15
Power .............................................................................................................................................................6–15
Energy............................................................................................................................................................6–15
A3 Event Recorder................................................................................................... 6–17
Event Data Clear.......................................................................................................................................6–17
Event Records ............................................................................................................................................6–17
A4 Product Information.......................................................................................... 6–21
Technical Support ....................................................................................................................................6–21
Revision Codes...........................................................................................................................................6–21
Calibration ...................................................................................................................................................6–22
Target and Flash Messages................................................................................... 6–23
Target Messages ......................................................................................................................................6–23
Self-test Errors ...........................................................................................................................................6–25
Flash Messages .........................................................................................................................................6–27
7:COMMISSIONING
General.........................................................................................................................7–1
Introduction ...................................................................................................................................................7–1
Testing Philosophy ......................................................................................................................................7–2
Safety Precautions......................................................................................................................................7–2
Conventions ...................................................................................................................................................7–2
Test Equipment.............................................................................................................................................7–3
Preliminary Work........................................................................................................7–5
Description .....................................................................................................................................................7–5
Dielectric Strength Testing......................................................................................................................7–6
Logic Inputs and Output Relays...............................................................................7–7
Logic Inputs....................................................................................................................................................7–7
Output Relays................................................................................................................................................7–8
Metering.......................................................................................................................7–9
Description .....................................................................................................................................................7–9
Current Inputs ...............................................................................................................................................7–9
Voltage Input ..............................................................................................................................................7–10
Transformer Type Selection ................................................................................................................7–11
Ambient Temperature Input................................................................................................................7–13
Analog outputs ..........................................................................................................................................7–14
Tap Position.................................................................................................................................................7–15
Protection Schemes ................................................................................................ 7–16
Precaution....................................................................................................................................................7–16
Harmonic Restrained Percent Differential....................................................................................7–16
Instantaneous Differential Protection ............................................................................................7–23
Phase Time Overcurrent .......................................................................................................................7–25
Phase Instantaneous Overcurrent 1 ...............................................................................................7–27
Phase Instantaneous Overcurrent 2 ...............................................................................................7–28
Neutral Time Overcurrent.....................................................................................................................7–29
Neutral Instantaneous Overcurrent 1 ............................................................................................ 7–31
Neutral Instantaneous Overcurrent 2 ............................................................................................ 7–32
Ground Time Overcurrent ....................................................................................................................7–32
Ground Instantaneous Overcurrent 1 ............................................................................................7–35
Ground Instantaneous Overcurrent 2 ............................................................................................7–36
Restricted Ground Fault Polarity Test .............................................................................................7–36
Restricted Ground Fault Element Test............................................................................................7–37
Negative-sequence Time Overcurrent...........................................................................................7–39
Negative-sequence Instantaneous Overcurrent.......................................................................7–42
Frequency ....................................................................................................................................................7–43
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
0–v
TABLE OF CONTENTS
Overexcitation ........................................................................................................................................... 7–52
Insulation Aging........................................................................................................................................ 7–54
Tap Monitor Failure ................................................................................................................................. 7–55
Auxiliary protection and monitoring functions ................................................. 7–56
THD Level Scheme................................................................................................................................... 7–56
Harmonic Derating Function.............................................................................................................. 7–57
Transformer Overload ........................................................................................................................... 7–58
Placing the Relay into Service ............................................................................... 7–60
Precautions................................................................................................................................................. 7–60
Procedure .................................................................................................................................................... 7–60
APPENDIX
Change Notes............................................................................................................. A–1
Revision History ...........................................................................................................................................A–1
Changes to the 745 Manual...................................................................................................................A–1
EU Declaration of Conformity ................................................................................. A–3
EU Declaration..............................................................................................................................................A–3
GE Multilin Warranty ................................................................................................ A–4
Warranty Statement..................................................................................................................................A–4
INDEX
0–VI
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
GE Consumer & Industrial
Multilin
745 Transformer Protection
System
Chapter 1: Getting Started
Getting Started
1.1
Important Procedures
1.1.1
Cautions and Warnings
Please read this chapter to guide you through the initial setup of your new relay.
WARNING
1.1.2
Inspection Checklist
•
Open the relay packaging and inspect the unit for physical damage.
•
View the rear nameplate and verify that the correct model has been ordered.
•
Ensure that the following items are included:
•
Note
CAUTION
Before attempting to install or use the relay, it is imperative that all
WARNINGS and CAUTIONS in this manual are reviewed to help
prevent personal injury, equipment damage, and/or downtime.
–
Instruction manual
–
GE EnerVista CD (includes software and relay documentation)
–
Mounting screws
For product information, instruction manual updates, and the latest software updates,
please visit the GE Multilin website at http://www.GEmultilin.com
If there is any noticeable physical damage, or any of the contents listed are missing,
please contact GE Multilin immediately.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
1–1
GETTING STARTEDCHAPTER 1: GETTING STARTED
1.1.3
Manual Organization
Reading a lengthy instruction manual on a new product is not a task most people enjoy. To
speed things up, this introductory chapter provides guidelines for basic relay usability.
Important wiring considerations and precautions discussed in Typical Wiring on page 3–7
should be observed for reliable operation. Detailed information regarding accuracy, output
relay contact ratings, and so forth are detailed in Specifications on page 2–5. The
remainder of this manual should be read and kept for reference to ensure maximum
benefit from the 745 Transformer Protection System. For further information, please
consult your local sales representative or the factory. Comments about new features or
modifications for your specific requirements are welcome and encouraged.
Setpoints and actual values are indicated as follows in the manual:
A2 METERING ZV LOSS OF LIFE Z HOTTEST-SPOT WINDING TEMPERATURE
This ‘path representation’ illustrates the location of a specific actual value or setpoint with
regards to its previous menus and sub-menus. In the example above, the HOTTEST-SPOT
WINDING TEMPERATURE actual value is shown to be an item in the LOSS OF LIFE submenu, which itself is an item in the A2 METERING menu, which is an item of ACTUAL
VALUES.
Sub-menu levels are entered by pressing the MESSAGE RIGHT or ENTER keys. When inside
a submenu, the MESSAGE LEFT or ESCAPE key returns to the previous sub-menu. The
MESSAGE UP and DOWN keys are used to scroll through the settings in a sub-menu. The
display indicates which keys can be used at any given point.
1–2
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 1: GETTING STARTEDGETTING STARTED
1.2
Using the Relay
1.2.1
Menu Navigation
Press the MENU key to access the header of each menu, which will be displayed in the
following sequence:
„ SETPOINTS
[ Z]
„ ACTUAL VALUES [Z]
„ TARGET MESSAGES [Z]
To access setpoints, press the MENU key until the display shows the header of the
setpoints menu, and then press the MESSAGE RIGHT or ENTER key to display the header for
the first setpoints page. The setpoint pages are numbered, have an ‘S’ prefix for easy
identification and have a name which provides a general idea of the settings available in
that page. Pressing the MESSAGE UP and DOWN keys will scroll through all the available
setpoint page headers. Setpoint page headers look as follows:
„ SETPOINTS
[ Z]
S1 745 SETUP
To enter a given setpoints page, press the MESSAGE RIGHT or ENTER key. Press the
MESSAGE UP or DOWN keys to scroll through sub-page headers until the required message
is reached. The end of a page is indicated by the message END OF PAGE. The beginning of a
page is indicated by the message TOP OF PAGE.
To access actual values, press the MENU key until the display shows the header of the
actual values menu, then press the MESSAGE RIGHT or ENTER key to display the header for
the first actual values page. The actual values pages are numbered, have an ‘A’ prefix for
easy identification and have a name, which gives a general idea of the information
available in that page. Pressing the MESSAGE UP or DOWN keys will scroll through all the
available actual values page headers. Actual values page headers look as follows:
„ ACTUAL VALUES [Z]
A1 STATUS
To enter a given actual values page, press the MESSAGE RIGHT or ENTER key. Press the
MESSAGE UP or DOWN keys to scroll through sub-page headers until the required message
is reached. The end of a page is indicated by the message END OF PAGE. The beginning of a
page is indicated by the message TOP OF PAGE.
Similarly, to access additional sub-pages, press the MESSAGE RIGHT or ENTER key to enter
the first sub-page, and then the MESSAGE UP or DOWN keys to scroll through the available
sub-pages, until the desired message is reached. The process is identical for both setpoints
and actual values.
The following procedure illustrates the key sequence to access the Current Demand actual
values.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
1–3
GETTING STARTEDCHAPTER 1: GETTING STARTED
1.
Press the MENU key until you reach the actual values main menu.
„ ACTUAL VALUES [Z]
2.
Press MESSAGE RIGHT or ENTER key to enter the first actual values page, and then the
MESSAGE UP or DOWN key to scroll through pages, until the A2 METERING DATA page
appears.
„ ACTUAL VALUES [Z]
A2 METERING DATA
3.
Press the MESSAGE RIGHT or ENTER key to display the first sub-page heading for the
Metering Data actual values page:
„ CURRENT
[Z]
METERING
Pressing the MESSAGE UP or DOWN keys will scroll the display up and down through the
sub-page headers. Pressing the MESSAGE LEFT or ESCAPE key at any sub-page heading will
return the display to the heading of the corresponding setpoint or actual value page, and
pressing it again, will return the display to the main menu header.
4.
Press the MESSAGE DOWN key until the ZERO-SEQUENCE CURRENT METERING subpage heading appears.
„ ZERO SEQUENCE [Z]
CURRENT METERING
5.
At this point, pressing MESSAGE RIGHT or ENTER key will display the messages under
this sub-page. If instead you press the MESSAGE UP key, it will return to the previous
sub-page heading. In this case,
„ POS. SEQUENCE [Z]
CURRENT METERING
6.
When the symbols „ and Z appear on the top line, it indicates that additional subpages are available and can be accessed by pressing the MESSAGE RIGHT or ENTER
key. Pressing MESSAGE RIGHT or ENTER while at the zero-sequence current metering
sub-page heading displays the following:
W1 NEG SEQ CURRENT:
0 A at 0° Lag
Pressing the MESSAGE LEFT key returns to the zero-sequence current metering sub-page
heading.
7.
Press the MESSAGE DOWN key to display the next actual value of this sub-page. Actual
values and setpoints messages always have a colon separating the name of the value
and the actual value or setpoint. This particular message displays the current demand
as measured by the relay.
The menu path to the value shown above is indicated as A2 METERING DATA ZV ZERO
SEQUENCE CURRENT METERING Z W1 NEG SEQ CURRENT. Setpoints and actual values
messages are referred to in this manner throughout the manual.
1–4
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 1: GETTING STARTEDGETTING STARTED
1.2.2
Panel Keying Example
For example, the S4 ELEMENTS ZV INSULATION AGING ZV AGING FACTOR LIMIT ZV AGING
FACTOR LIMIT PICKUP path representation describes the following key-press sequence:
1.
Press the MENU key until the setpoints header appears on the display.
„ SETPOINTS
2.
[ Z]
Press the MESSAGE RIGHT or ENTER key, and then the MESSAGE DOWN key until the S4
ELEMENTS message is displayed.
„ SETPOINTS
[ Z]
S4 ELEMENTS
3.
Press the MESSAGE RIGHT or ENTER key to display INSULATION AGING message.
„ INSULATION
[ Z]
AGING
4.
Press the MESSAGE RIGHT or ENTER key to display AGING FACTOR LIMIT message.
„ AGING FACTOR [Z]
LIMIT
5.
Press the MESSAGE RIGHT or ENTER key to reach the AGING FACTOR LIMIT PICKUP
message and the corresponding setpoint value.
AGING FACTOR LIMIT
PICKUP: 2.0
6.
Press the MESSAGE DOWN key to display the next actual value message as shown
below:
AGING FACTOR LIMIT
DELAY: 10 min.
7.
Pressing the MESSAGE UP or DOWN keys scrolls the display up and down through all
the setpoint displays in this corresponding sub-page.
8.
Pressing the MESSAGE LEFT key reverses the process described above and returns the
display to the previous level.
„ AGING FACTOR [Z]
LIMIT
9.
Press the MESSAGE LEFT key twice to return to the S4 ELEMENTS page header.
„ SETPOINTS
[ Z]
S4 ELEMENTS
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
1–5
GETTING STARTEDCHAPTER 1: GETTING STARTED
1.3
Changing Setpoints
1.3.1
Introduction
There are several different classes of setpoints, distinguished by the way their values are
displayed and edited. This section describes how to edit the values used by all setpoint
classes.
Hardware and passcode security features are designed to provide protection against
unauthorized setpoint changes. Since we will be programming new setpoints using the
front panel keys, a hardware jumper must be installed across the setpoint access terminals
(D9 and D10) on the back of the relay case. A keyswitch may also be used across these
terminals to enable setpoint access. Attempts to enter a new setpoint via the front panel
without this connection will be unsuccessful.
1.3.2
Using the HELP Key
Each numerical setpoint has its own minimum, maximum, and increment value associated
with it. These parameters define what values are acceptable for a setpoint.
1.
Select the S2 SYSTEM SETUP ZV VOLTAGE INPUT ZV NOMINAL VT SECONDARY
VOLTAGE setpoint.
NOMINAL VT SECONDARY
VOLTAGE: 120.0 V
2.
Press HELP. The following context sensitive flash message will appear for several
seconds. For the case of a numerical setpoint message, the HELP key displays the
minimum, maximum, and step value.
Range: 60.0
to 120.0 by 0.1
1.3.3
Numerical Setpoints
The following two methods of editing and storing a numerical setpoint value are available.
1–6
1.
0 to 9 and the decimal key: The relay numeric keypad works the same as that of any
electronic calculator. A number is entered one digit at a time. The left-most digit is
entered first and the right-most digit is entered last. Pressing the ESCAPE key, before
the ENTER key, returns the original value to the display.
2.
VALUE keys: The VALUE UP key increments the displayed value, by the step value, up to
the maximum value allowed. While at the maximum, pressing the VALUE UP key again
will allow setpoint selection to continue from the minimum value. The VALUE DOWN
key decrements the displayed value, by the step value, down to the minimum value.
Again, continuing to press the VALUE DOWN key while at the minimum value will
continue setpoint selection from the maximum value.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 1: GETTING STARTEDGETTING STARTED
As an example, let’s set the nominal VT secondary voltage setpoint to 69.3 V. Press the
appropriate numeric keys in the sequence ‘6 9 . 3‘. The display message will change as
the digits are being entered.
NOMINAL VT SECONDARY
VOLTAGE: 69.3 V
Editing changes are not registered until the ENTER key is pressed. Press the ENTER key to
store the new value in memory. This flash message momentarily appears to confirmation
the storing process. If 69.28 were entered, the value is automatically rounded to 69.3, since
the step value for this setpoint is 0.1.
NEW SETPOINT HAS
BEEN STORED
1.3.4
Enumeration Setpoints
Enumeration setpoints have data values which are part of a set, whose members are
explicitly defined by a name. A set is comprised of two or more members.
Enumeration type values are changed using the VALUE keys. The VALUE UP key displays
the next selection while the VALUE DOWN key displays the previous selection. As an
example we may need to set the phase sequence to ACB. Press the VALUE keys until the
proper selection is displayed.
PHASE SEQUENCE:
ACB
Editing changes are not registered until ENTER is pressed, storing the new value in
memory. This flash message momentarily appears to confirm the storing process.
NEW SETPOINT HAS
BEEN STORED
1.3.5
Text Setpoints
Text setpoints have data values which are fixed in length, but user defined in character.
They may be comprised of upper case letters, lower case letters, numerals, and a selection
of special characters.
The editing and storing of a text value is accomplished with the use of the decimal, ENTER,
VALUE, and ESCAPE keys. For example:
1.
The name for output relay 3 should be more descriptive than the default value. For this
example let us rename output relay as INST DIFF TRIP. Press the decimal key and an
underscore (_) will appear at the first character position.
OUTPUT 3 NAME:
Trip 3
2.
Press VALUE keys until the character “I” is displayed in the first position, then press the
decimal key to store the character and advance the cursor. Change the second
character to a “N” using the VALUE keys and save this change by pressing the decimal
key again. Continue editing all the characters in the text until the string INST DIFF TRIP
is entered. Note that a space is selected like a character. If a character is entered
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
1–7
GETTING STARTEDCHAPTER 1: GETTING STARTED
incorrectly, press the decimal key repeatedly until the cursor returns to the position of
the error and re-enter the character as required. Once complete, press ENTER to
remove the solid cursor and save the result.
OUTPUT 3 NAME:
INST DIFF TRIP
1–8
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 1: GETTING STARTEDGETTING STARTED
1.4
Security
1.4.1
Installation
Note that the relay is defaulted to the “Not Programmed” state before it leaves the factory.
This safeguards against the installation of a relay whose setpoints have not been entered.
In addition, a relay in the “Not Programmed” state blocks signaling of any output relay, and
turns off the In Service LED indicator.
Move to the S1 745 SETUP ZV INSTALLATION ZV 745 SETPOINTS message. To put the relay
in the “Programmed” state, press the VALUE UP or DOWN key once and press ENTER. Enter
“Yes” for the ARE YOU SURE? message. The In Service LED indicator will now turn on.
745 SETPOINTS:
Not Programmed
1.4.2
Changing the Passcode
To guarantee that the relay settings cannot be tampered with, the user may setup the
passcode security feature.
1.
Move to the S1 745 SETUP Z PASSCODE Z SETPOINT ACCESS message. This message
cannot be edited directly. It simply indicates whether passcode security is enabled
(SETPOINT ACCESS: “Read Only”), or passcode security is disabled (SETPOINT ACCESS:
“Read & Write”). Each relay is shipped from the factory with setpoint access allowed.
The passcode is also defaulted to '0', which disables the passcode security feature
entirely.
SETPOINT ACCESS:
Read & Write
2.
Press the MESSAGE DOWN key once.
CHANGE PASSCODE?
No
3.
Press the VALUE UP or VALUE DOWN key once.
CHANGE PASSCODE?
Yes
4.
Press the ENTER key to begin the procedure of changing the passcode. The displayed
message will change as shown. The current passcode is '0', so press the '0' numeric
key. The relay will acknowledge the key press by displaying ‘*’.
PLEASE ENTER CURRENT
PASSCODE:
5.
Press the ENTER key.
ENTER NEW PASSCODE
FOR ACCESS:
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
1–9
GETTING STARTEDCHAPTER 1: GETTING STARTED
6.
For this example, change the passcode to “123” by pressing the appropriate numeric
keys in the ‘1 2 3’ sequence. The message will change as the digits are entered, with
the end result being as shown.
ENTER NEW PASSCODE
FOR ACCESS:
***
7.
Press the ENTER key to store the new passcode and a confirmation message appears.
As a safety measure, the relay requires you to enter a new passcode twice. This
ensures the passcode has been entered correctly.
PLEASE RE-ENTER NEW
PASSCODE:
8.
After pressing the appropriate numeric keys in the sequence ‘1 2 3’, press ENTER. This
flash message appears momentarily on the display and confirms the new passcode is
stored in memory.
NEW PASSCODE
HAS BEEN STORED
9.
After a few seconds, the original display returns.
10. Press the MESSAGE UP key. As soon as a non-zero passcode is entered, setpoint
access will automatically become restricted.
ALLOW ACCESS TO
SETPOINTS? No
1.4.3
Disabling and Enabling Passcode Security
Suppose at some time in the future you want to alter a setpoint. In order to do this, you
must first disable passcode security, make the setpoint change, and then re-enable the
passcode security.
1.
Move to message S1 745 SETUP Z PASSCODE ZV ALLOW ACCESS TO SETPOINTS. It is
from here that we will disable passcode security. Please note that this message is
hidden, when the passcode security feature is disabled by entering a passcode of “0”.
ALLOW ACCESS TO
SETPOINTS? No
2.
Press the VALUE UP or DOWN key once to select “Yes” and press ENTER. The displayed
message will change as shown.
PLEASE ENTER CURRENT
PASSCODE:
3.
Enter the current passcode and press the ENTER key. This flash message indicates
that the keyed in value was accepted and that passcode security is now disabled.
SETPOINT ACCESS
IS NOW ALLOWED
1–10
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 1: GETTING STARTEDGETTING STARTED
4.
This message will appear after a few seconds. Now that setpoint access is enabled,
the ALLOW ACCESS TO SETPOINTS message has been replaced by the RESTRICT
ACCESS TO SETPOINTS message. The relay’s setpoints can now be altered and stored.
If no front panel keys are pressed for longer than 30 minutes, setpoint access will
automatically become restricted again.
RESTRICT ACCESS TO
SETPOINTS? No
5.
To disable setpoint access, immediately after setpoint editing, move back to message
S1 745 SETUP Z PASSCODE ZV RESTRICT ACCESS TO SETPOINTS and enter “Yes”. Key
the current passcode into the shown message.
PLEASE ENTER CURRENT
PASSCODE:
6.
Press the ENTER key and this message will flash on the display. It indicates that
passcode security is now enabled.
SETPOINT ACCESS
IS NOW RESTRICTED
7.
After a few seconds, the original display returns.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
1–11
GETTING STARTEDCHAPTER 1: GETTING STARTED
1–12
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
GE Consumer & Industrial
Multilin
745 Transformer Protection
System
Chapter 2: Overview
Overview
2.1
Introduction
2.1.1
Description
These instructions do not purport to cover all details or variations in equipment nor provide
for every possible contingency to be met in connection with installation, operation, or
maintenance. Should further information be desired or should particular problems arise
which are not covered sufficiently for the purchaser’s purpose, the matter should be
referred to the General Electric company.
To the extent required the products described herein meet applicable ANSI, IEEE, and
NEMA standards; but no such assurance is given with respect to local codes and
ordinances because they vary greatly.
The 745 Transformer Protection System™ is a high speed, multi-processor based, threephase, two or three winding, transformer management relay intended for the primary
protection and management of small, medium and large power transformers. The 745
combines percent differential, overcurrent, frequency, and overexcitation protection
elements along with monitoring of individual harmonics, and total harmonic distortion
(THD) in one economical package.
The relay provides a variety of adaptive relaying features:
•
Adaptive harmonic restraint which addresses the problem of false tripping during
inrush
•
Adaptive time overcurrent elements which will adjust their pickup settings based on
the calculated transformer capability when supplying load currents with high
harmonic content
•
Multiple setpoint groups which allow the user to enter and dynamically select from up
to four groups of relay settings to address the protection requirements of different
power system configurations
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
2–1
OVERVIEWCHAPTER 2: OVERVIEW
•
Dynamic CT ratio mismatch correction which monitors the on-load tap position and
automatically corrects for CT ratio mismatch
•
FlexLogic™ which allows PLC style equations based on logic inputs and protection
elements to be assigned to any of the 745 outputs.
The 745 also includes a powerful testing and simulation feature. This allows the protection
engineer the ability to test the relay operation based on captured or computer generated
waveform data which can be converted to a digitized format and downloaded into the
745’s simulation buffer for “playback”. A waveform capture function that records waveform
data for fault, inrush, or alarm conditions is also provided.
The auto-configuration function eliminates the need for any special CT connections by
having all CTs connected in wye.
2.1.2
Protection Features
The following table outlines the protection features available for windings 1, 2, and 3, as
well as the common protection elements.
Symbol
Common protection element
Symbol
Winding 1 protection elements
59/81-1
Volts-per-hertz 1
150/46
Negative sequence instantaneous overcurrent
59/81-2
Volts-per-hertz 2
151/46
Negative sequence time overcurrent
81U-1
Underfrequency 1
150P1
Phase instantaneous overcurrent 1
81U-2
Underfrequency 2
150P2
Phase instantaneous overcurrent 2
81U-R1
Frequency decay rate 1
150N1
Neutral (3I0) instantaneous overcurrent 1
81U-R2
Frequency decay rate 2
150N2
Neutral (3I0) instantaneous overcurrent 2
81U-R3
Frequency decay rate 3
150G1
Ground instantaneous overcurrent 1
81U-R4
Frequency decay rate 4
150G2
Ground instantaneous overcurrent 2
81-H5
5th harmonic Level
151P
Phase time overcurrent
81O
Overfrequency
151N
Neutral (3I0) time overcurrent
87
Differential (percent)
151G
Ground time overcurrent
50/87
Instantaneous differential
187TG
Ground differential (restricted ground fault)
AN-1
Analog input level 1
1THD
Total harmonic distortion level
AN-2
Analog input level 2
1AD
Current demand
---
Insulation aging: aging factor, hottest spot limit,
and total accumulated life
---
Tap changer monitor
2–2
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 2: OVERVIEWOVERVIEW
Symbol
Winding 2 protection elements
Symbol
Winding 3 protection elements
250/46
Negative sequence instantaneous overcurrent
350/46
Negative sequence instantaneous overcurrent
251/46
Negative sequence time overcurrent
351/46
Negative sequence time overcurrent
250P1
Phase instantaneous overcurrent 1
350P1
Phase instantaneous overcurrent 1
250P2
Phase instantaneous overcurrent 2
350P2
Phase instantaneous overcurrent 2
250N1
Neutral (3I0) instantaneous overcurrent 1
350N1
Neutral (3I0) instantaneous overcurrent 1
250N2
Neutral (3I0) instantaneous overcurrent 2
350N2
Neutral (3I0) instantaneous overcurrent 2
250G1
Ground instantaneous overcurrent 1
351P
Phase time overcurrent
250G2
Ground instantaneous overcurrent 2
351N
Neutral (3I0) time overcurrent
251P
Phase time overcurrent
351G
Ground time overcurrent
251N
Neutral (3I0) time overcurrent
387TG
Ground differential (restricted ground fault)
251G
Ground time overcurrent
3THD
Total harmonic distortion level
287TG
Ground differential (restricted ground fault)
3AD
Current demand
2THD
Total harmonic distortion level
2AD
Current demand
FIGURE 2–1: Single line diagram
2.1.3
Order Codes
The order codes for the 745 Transformer Protection System are shown below.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
2–3
OVERVIEWCHAPTER 2: OVERVIEW
Table 2–1: 745 order codes
Base unit
Windings per
phase
745 –
745
* –
|
W2
W3
Phase current
input ratings
Ground current
input ratings
Control power
Options
Display/Ethernet
Harsh environment
2–4
* –
|
|
|
P1
P5
P15
P51
P115
P151
P155
P511
P515
P551
* –
|
|
|
|
|
|
|
|
|
|
|
|
|
G1
G5
G15
G51
* –
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
LO
HI
* –
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
A
L
R
* –
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
B
E
T
*
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
H
745 Transformer Protection System
Two windings per phase
Three windings per phase
Winding 1 = 1 A, Winding 2 = 1 A, Winding 3 = 1 A
Winding 1 = 5 A, Winding 2 = 5 A, Winding 3 = 5 A
Winding 1 = 1 A, Winding 2 = 5 A
Winding 1 = 5 A, Winding 2 = 1 A
Winding 1 = 1 A, Winding 2 = 1 A, Winding 3 = 5 A
Winding 1 = 1 A, Winding 2 = 5 A, Winding 3 = 1 A
Winding 1 = 1 A, Winding 2 = 5 A, Winding 3 = 5 A
Winding 1 = 5 A, Winding 2 = 1 A, Winding 3 = 1 A
Winding 1 = 5 A, Winding 2 = 1 A, Winding 3 = 5 A
Winding 1 = 5 A, Winding 2 = 5 A, Winding 3 = 1 A
Winding 1/2 = 1 A, Winding 2/3 = 1 A
Winding 1/2 = 5 A, Winding 2/3 = 5 A
Winding 1/2 = 1 A, Winding 2/3 = 5 A
Winding 1/2 = 5 A, Winding 2/3 = 1 A
20 to 60 V DC; 20 to 48 V AC at 48 to 62 Hz
90 to 300 V DC; 70 to 265 V AC at 48 to 62 Hz
Analog inputs/outputs
Loss of life
Restricted ground fault
Basic display
Enhanced display, larger LCD
Enhanced display, larger LCD, with Ethernet (10Base-T)
Harsh (chemical) environment conformal coating
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 2: OVERVIEWOVERVIEW
2.2
Specifications
2.2.1
Applicability
TRANSFORMERS AND FREQUENCY
Transformers:...................................................two-winding or three-winding
Frequency:.........................................................50 or 60 Hz nominal
Frequency tracking: ......................................40 to 65 Hz for 0.05 × CT < current ≤ 1 × CT
5 to 65 Hz for current > 1 × CT
2 to 65 Hz for voltage > 50% of VT (only if voltage sensing
is enabled)
2.2.2
Inputs
CONTROL POWER
Options:...............................................................LO/HI (specified when ordering)
LO range:............................................................20 to 60 V DC; 20 to 48 V AC at 48 to 62 Hz
HI range:.............................................................90 to 300 V DC; 70 to 265 V AC at 48 to 62 Hz
Power:..................................................................30 VA nominal, 40 VA maximum
Total loss of voltage ride-through time (0% control power): 16.7 ms
Fuse current rating:.......................................3.15 A (fuse not accessible)
Fuse type:...........................................................5 × 20 mm slow-blow Littelfuse, high breaking capacity;
model 2153.15
PHASE CURRENT INPUT
Source CT:..........................................................1 to 50000 A primary; 1 or 5 A secondary
Relay input:........................................................1 A or 5 A (specified at order)
Burden:................................................................less than 0.2 VA at rated load per phase
Conversion range:..........................................0.02 to 46 × CT at 50/60 Hz nominal frequency
Accuracy at < 4 × CT:....................................±0.25% of 4 × CT (±0.01 × CT) at 50/60 Hz nominal
frequency
Accuracy at ≥ 4 × CT:....................................±0.5% of 46 × CT (±0.2 × CT) at 50/60 Hz nominal
frequency
Overload withstand:......................................1 second at 80 times rated current; 2 seconds at 40 times
rated current; continuous at 3 times rated current
GROUND CURRENT INPUT
Source CT:..........................................................1 to 50000 A primary, 1 or 5 A secondary
Relay input:........................................................1 A or 5 A (specified at order)
Burden:................................................................less than 0.2 VA at rated load
Conversion range:..........................................0.02 to 46 × CT
Accuracy at < 4 × CT:....................................±0.25% of 4 × CT (±0.01 × CT)
Accuracy at ≥ 4 × CT:....................................±0.5% of 46 × CT (±0.2 × CT)
Overload withstand:......................................1 second at 80 times rated current; 2 seconds at 40 times
rated current; continuous at 3 times rated current
VOLTAGE INPUTS
Source VT: ..........................................................2 to 600 kV / 60 to 120 V
Source VT ratio: ...............................................1 to 5000 in steps of 1
Relay input:........................................................60 to 120 V phase-neutral
Burden:................................................................less than 0.025 VA at 120 V
Maximum continuous input: 273 V
Maximum accuracy input: 260 V (full-scale)
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
2–5
OVERVIEWCHAPTER 2: OVERVIEW
Accuracy:............................................................±2.0% of full-scale
LOGIC INPUTS
Number of inputs: ..........................................16
Dry contacts: ....................................................1000 Ω maximum ON resistance (32 V DC at 2 mA
provided by the 745)
Wet contacts: ...................................................30 to 300 V DC at 1.5 mA
ANALOG INPUT
Type: .....................................................................DC mA
Ranges:................................................................0 to 1 mA, 0 to 5 mA, 0 to 20 mA, 4 to 20 mA
(programmable)
Input impedance: ...........................................375 Ω ±10%
Conversion range:..........................................0 to 21 mA
Accuracy:............................................................±1% of full scale (based on input range)
TAP POSITION
Type: .....................................................................resistance (ohms)
Range:..................................................................0 to 500 Ω or 0.5 to 5.0 kΩ
Bias current:......................................................1 mA or 10 mA (based on input range)
Accuracy:............................................................±1% of full scale (based on input range)
RTD
Type: .....................................................................3 wire
RTD Type.............................................................100 Ω Platinum (DIN.43760), 100 Ω Nickel, 120 Ω Nickel
IRIG-B INPUT
Amplitude-modulated:.................................1.0 to 10 V pk-pk
DC shift:...............................................................TTL
Input impedance: ...........................................70 to 100 kΩ
2.2.3
Protection Elements
PERCENT DIFFERENTIAL
Operating current pickup: 0.05 to 1.00 × CT in steps of 0.01
Dropout level: ...................................................97 to 98% of pickup
Slope 1 range: ..................................................15% to 100% in steps of 1
Slope 2 range: ..................................................50% to 100% in steps of 1
KP (Slope-1 kneepoint): ................................1.0 to 20.0 × CT in steps of 0.1
Harmonic restraint: .......................................0.1 to 65.0% in steps of 0.1
Solid state output operate time:
pickup < 1 × CT: ........................42 to 52 ms
1 × CT < pickup < 1.1 × kneepoint: 34 to 44 ms
pickup > 1.1 × kneepoint:......26 to 36 ms
Relay outputs 2 to 5 operate time:
pickup < 1 × CT:.........................46 to 56 ms
1 × CT < pickup < 1.1 × kneepoint: 38 to 48 ms
pickup > 1.1 × kneepoint:......30 to 40 ms
INSTANTANEOUS DIFFERENTIAL OVERCURRENT
Pickup level:.......................................................3.00 to 20.00 × CT in steps of 0.01
Dropout level: ...................................................97 to 98% of pickup
Level accuracy:................................................per current input
2–6
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 2: OVERVIEWOVERVIEW
Solid state output operate time:
at 1.2 × pickup: ......................... 22 to 30 ms
at 2.0 × pickup: ......................... 18 to 26 ms
at 4.0 × pickup: ......................... 11 to 19 ms
Relay outputs 2 to 5 operate time:
at 1.2 × pickup: ......................... 28 to 36 ms
at 2.0 × pickup: ......................... 24 to 32 ms
at 4.0 × pickup: ......................... 17 to 25 ms
PHASE / NEUTRAL / GROUND / NEGATIVE SEQUENCE TIME OVERCURRENT
Pickup level: ......................................................0.05 to 20.00 × CT in steps of 0.01
Dropout level: ...................................................97 to 98% of pickup
Curve shapes: ..................................................ANSI extremely/very/moderately/normally inverse;
definite time (0.1 s base curve); IEC curve A/B/C and short;
FlexCurve™ A/B/C (programmable curves); IAC extreme/
very/inverse/short
Curve multiplier: .............................................0.00 to 100.00 in steps of 0.01
Reset type: .........................................................instantaneous or linear
Level accuracy: ...............................................per current input
Timing accuracy:............................................±3% of trip time or ±20 ms (whichever is greater) at ≥ 1.03
× pickup
PHASE / NEUTRAL / GROUND / NEGATIVE SEQUENCE INSTANTANEOUS OVERCURRENT
Pickup level: ......................................................0.05 to 20.00 × CT in steps of 0.01
Dropout level: ...................................................97 to 98% of pickup
Time delay:........................................................0 to 60000 ms in steps of 1
Level accuracy: ...............................................per current input
Solid state output operate time:
at 1.2 × pickup: ......................... 22 to 30 ms
at 2.0 × pickup: ......................... 18 to 26 ms
at 4.0 × pickup: ......................... 11 to 19 ms
Relay outputs 2 to 5 operate time:
at 1.2 × pickup: ......................... 28 to 36 ms
at 2.0 × pickup: ......................... 24 to 32 ms
at 4.0 × pickup: ......................... 17 to 25 ms
RESTRICTED GROUND FAULT
Number of elements:....................................2
Minimum pickup: ............................................0.02 to 20.00 × CT in steps of 0.01
Dropout level: ...................................................97 to 98% of pickup
Slope range:......................................................0 to 100% in steps of 1
Pickup delay:.....................................................0.00 to 600.00 s in steps of 0.01
Solid-state output operating time:
at 1.1 × pickup: 30 to 50 ms
at 10 × pickup: 20 to 30 ms
(delay set at 0.0 s)
Relay outputs 2 to 5 operating time:
at 1.1 × pickup: 30 to 50 ms
at 10 × pickup: 20 to 30 ms
(delay set at 0.0 s)
UNDERFREQUENCY
Number of elements:....................................2
Operating current pickup: 0.05 to 1.00 × CT in steps of 0.01
Operating voltage pickup: 0.10 to 0.99 × VT in steps of 0.01
Pickup level: ......................................................45.00 to 59.99 Hz in steps of 0.01
Dropout level: ...................................................pickup + 0.03 Hz
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
2–7
OVERVIEWCHAPTER 2: OVERVIEW
Time delay: ........................................................0.00 to 600.00 s in steps of 0.01
Signal source:...................................................winding 1 phase A current / voltage
Level accuracy:................................................±0.02 Hz
Solid state output operate time: 39 to 60 ms at 3% beyond pickup (delay set at 0.0 s)
Relay outputs 2 to 5 operate time: 42 to 66 ms at 3% beyond pickup (delay set at 0.0 s)
FREQUENCY RATE OF CHANGE
Number of elements:....................................4
Operating current pickup: 0.05 to 1.00 × CT in steps of 0.01
Operating voltage pickup: 0.10 to 0.99 × VT in steps of 0.01
Pickup level:.......................................................45.00 to 59.99 Hz in steps of 0.01
Dropout level: ...................................................pickup + 0.03 Hz
Rate 1/2/3/4: ....................................................0.1 to 5.0 Hz/sec. in steps of 0.1
Dropout level: ...................................................pickup + 0.07 Hz/sec.
Signal source:...................................................winding 1 phase A current / voltage
Level accuracy:................................................±0.02 Hz
Operate time: ...................................................The operate time of this element is variable and is
dependent on the decay rate setting and the supervision
frequency level.
OVERFREQUENCY
Operating current pickup: 0.05 to 1.00 × CT in steps of 0.01
Operating voltage pickup: 0.10 to 0.99 × VT in steps of 0.01
Pickup level:.......................................................50.01 to 65.00 Hz in steps of 0.01
Dropout level: ...................................................pickup – 0.03 Hz
Time delay: ........................................................0.00 to 600.00 s in steps of 0.01
Signal source:...................................................winding 1 phase A current / voltage
Level accuracy:................................................±0.02 Hz
Solid state output operate time: 39 to 60 ms at 3% beyond pickup (delay set at 0.0 s)
Relay outputs 2 to 5 operate time: 42 to 66 ms at 3% beyond pickup (delay set at 0.0 s)
OVEREXCITATION ON VOLTS PER HERTZ
Number of elements:....................................2
Operating voltage pickup: 0.10 to 0.99 × VT in steps of 0.01
Pickup level:.......................................................1.00 to 4.00 V/Hz in steps of 0.01
Curve shapes: ..................................................definite time (0.1 second base curve); IEC curve A/B/C
Time delay: ........................................................0.00 to 600.00 s in steps of 0.01
Reset delay:.......................................................0.0 to 6000.0 s in steps of 0.1
Signal source:...................................................voltage
Range:..................................................................10 to 65 Hz
Level accuracy: .....................................±0.02 V/Hz
Solid state output operate time: 165 to 195 ms at 1.10 × pickup:
Relay outputs 2 to 5 operate time: 170 to 200 ms (delay set at 0.0 s) at 1.10 × pickup
OVEREXCITATION ON FIFTH HARMONIC LEVEL
Operating current pickup: 0.03 to 1.00 × CT in steps of 0.01
Pickup level:.......................................................0.1 to 99.9 in steps of 0.1%
Dropout:..............................................................95% of pickup
Time delay: ........................................................0 to 60000 s in steps of 1 s
Signal source:...................................................all phase currents
Solid state output operate time: 20 to 120 ms at 1.10 × pickup
Relay outputs 2 to 5 operate time: 25 to 125 ms (delay set at 0.0 s) at 1.10 × pickup
2–8
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 2: OVERVIEWOVERVIEW
INSULATION AGING
Hottest spot limit:
Pickup level: ............................... 50 to 300°C in steps of 1
Delay: ............................................ 0 to 60000 min. in steps of 1
Aging factor limit:
Pickup level:................................ 1.1 to 10.0 in steps of 0.1
Delay: ............................................ 0 to 60000 min. in steps of 1
Loss of life limit:
Pickup level:................................ 0 to 20000 × 10 h in steps of 1
2.2.4
Outputs
ANALOG OUTPUTS
Number of outputs:.......................................7
Output range:...................................................0 to 1 mA, 0 to 5 mA, 0 to 10 mA, 0 to 20 mA, or 4 to 20
mA
Maximum load:................................................10 kΩ at 0 to 1 mA
600 Ω at 4 to 20 mA
Isolation: .............................................................fully isolated
Accuracy: ...........................................................±1% of full scale
SOLID STATE OUTPUT
Maximum ratings:..........................................make and carry 15 A at 250 V DC for 500 ms
TRIP RELAYS 2 TO 5
Configuration:..................................................form-A (breaker trip rated)
Contact material: ...........................................silver alloy
Max. ratings: .....................................................300 V AC, 250 V DC, 15 A, 1500 VA
Make/carry:.......................................................20 A continuous; 40 A for 0.2 s (DC voltage); 80 A for 0.2 s
(AC voltage)
Voltage
DC resistive
DC inductive
L/R = 40 ms
AC resistive
AC inductive
PF = 0.4
Break
Maximum load
30 V DC
10 A
300 W
125 V DC
0.8 A
300 W
250 V DC
0.4 A
300 W
30 V DC
5A
150 W
125 V DC
0.3 A
150 W
250 V DC
0.2 A
150 W
120 V AC
20 A
5000 VA
240 V AC
20 A
5000 VA
120 V AC
8A
5000 VA
240 V AC
7A
5000 VA
AUXILIARY 6 TO 8 RELAYS, SELF-TEST RELAY 9
Configuration:..................................................form-C
Contact material: ...........................................silver alloy
Maximum ratings:..........................................300 V AC, 250 V DC, 15 A, 1500 VA
Make/carry:.......................................................10 A continuous; 30 A for 0.2 s
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
2–9
OVERVIEWCHAPTER 2: OVERVIEW
Voltage
DC resistive
DC inductive
L/R = 40 ms
AC resistive
AC inductive
PF = 0.4
2.2.5
Break
Maximum load
30 V DC
10 A
300 W
125 V DC
0.5 A
62.5 W
250 V DC
0.3 A
75 W
30 V DC
5A
150 W
125 V DC
0.25 A
31.3 W
250 V DC
0.15 A
37.5 W
120 V AC
10 A
2770 VA
240 V AC
10 A
2770 VA
120 V AC
4A
480 VA
240 V AC
3A
750 VA
Miscellaneous
COMMUNICATIONS
All ports: ..............................................................300 to 19200 baud, programmable parity, Modbus RTU
protocol, DNP
Ethernet: .............................................................10Base-T RJ45 connector
Modbus TCP/IP
Version 2.0 / IEEE 802.3
CLOCK
Resolution: .........................................................1 ms
Accuracy.............................................................±1 ms with IRIG-B
±1 minute/month without IRIG-B
Supercap backup life:...................................45 days when control power is off
HARMONICS
Range:..................................................................0.00 to 99.9%
Accuracy: ...............................................±1% of full-scale at 0.5 × CT
THD
Range:..................................................................0.00 to 99.9%
Accuracy:............................................................±1% of full-scale at 0.5 × CT
EVENT RECORDER
Number of events: .........................................256
Event content:..................................................see Types and causes of events on page 6–19
OPERATING ENVIRONMENT
Operating temperature: .............................. –40°C to +60°C
Storage temperature:...................................–40°C to +80°C ambient
Humidity: ............................................................up to 90% non-condensing
Altitude: ...............................................................2000 m
Pollution degree:.............................................II
CASE
Drawout:.............................................................Fully drawout unit (automatic CT shorts)
Seal: ......................................................................Seal provision
Door:.....................................................................Dust tight door
Panel:....................................................................Panel or 19-inch rack mount
Weight (case and relay):..............................18 lbs., 6 oz. (8.4 kg)
IP class:................................................................X0
2–10
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 2: OVERVIEWOVERVIEW
PRODUCTION TESTS
Thermal:..............................................................operational test at ambient then increasing to 60°C
Dielectric strength: ........................................per UL 508 section 67A on CT inputs, VT inputs, control
power inputs, switch inputs, and relay outputs (1.9 kV AC
for 1 second)
TYPE WITHSTAND TESTS
The following table lists the 745 type tests:
Standard
GE Multilin
Test Name
Level
Temperature Cycling
–50°C to +80°C
IEC 60068-2-30
Relative Humidity Cyclic
55°C at 95% RH
IEC 60068-2-38
Composite Temperature/Humidity
65/–10°C at 93% RH
IEC 60255-5
Dielectric Strength
2300 V AC
IEC 60255-5
Impulse Voltage
5 kV
IEC 60255-21-1
Sinusoidal Vibration
2g
IEC 60255-22-1
Damped Oscillatory Burst, 1 MHz
2.5 kV / 1 kV
IEC 60255-22-2
Electrostatic Discharge: Direct
8 kV
IEC 60255-22-3
Radiated RF Immunity
10 V/m
IEC 60255-22-4
Electrical Fast Transient / Burst Immunity
4 kV
IEC 60255-22-5
Surge Immunity
4 kV / 2 kV
IEC 60255-22-6
Conducted RF Immunity, 150 kHz to 80 MHz
10 V/m
IEC 60255-25
Radiated RF Emission
Group 1 Class A
IEC 60255-25
Conducted RF Emission
Group 1 Class A
IEC 60529
Ingress of Solid Objects and Water (IP)
IP40 (front), IP20 (back)
IEC 61000-4-8
Power Frequency Magnetic Field Immunity
30 A/m
IEC 61000-4-9
Pulse Magnetic Field Immunity
1000 A/m
IEC 61000-4-11
Voltage Dip; Voltage Interruption
0%, 40%, 100%
IEEE C37.90.1
Fast Transient SWC
4 kV / 4 kV
IEEE C37.90.1
Oscillatory Transient SWC
2.5 kV / 2.5 kV
APPROVALS
ACA:.......................................................................Tick mark
RF Emissions for Australia
CE:..........................................................................Conforms to IEC 1010-1 / EN 50082-2
EN: .........................................................................EN 50623
EMC - CE for Europe
FCC:.......................................................................Part 15; RF Emissions for North America
IEC:.........................................................................IEC 1010-1
LVD - CE for Europe
UL:..........................................................................UL listed for the USA and Canada, E83849
Note
Note
It is recommended that all relays must be powered up once per year, for one hour
continuously, to avoid deterioration of electrolytic capacitors and subsequent relay
failure.
Specifications subject to change without notice.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
2–11
OVERVIEWCHAPTER 2: OVERVIEW
2–12
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
GE Consumer & Industrial
Multilin
745 Transformer Protection
System
Chapter 3: Installation
Installation
3.1
Drawout Case
3.1.1
Case Description
The 745 is packaged in the standard SR-series arrangement, which consists of a drawout
relay and a companion case. The case provides mechanical protection for the drawout
portion, and is used to make permanent electrical connections to external equipment.
Where required, case connectors are fitted with mechanisms, such as automatic CT
shorting, to allow the safe removal of the relay from an energized panel. There are no
electronic components in the case.
FIGURE 3–1: Case dimensions
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
3–1
INSTALLATIONCHAPTER 3: INSTALLATION
3.1.2
Panel Cutout
A 745 can be mounted alone or adjacent to another SR-series unit on a standard 19” rack
panel. Panel cutout dimensions for both conditions are as shown. When planning the
location of your panel cutout, ensure provision is made for the front door to swing open
without interference to or from adjacent equipment.
FIGURE 3–2: Single SR-series relay panel cutout
FIGURE 3–3: Double SR-series relay panel cutout
3.1.3
Case Mounting
Before mounting the SR unit in the supporting panel, remove the relay portion from its
case, as described in the next section. From the front of the panel, slide the empty case
into the cutout. To ensure the front bezel sits flush with the panel, apply pressure to the
bezel’s front while bending the retaining tabs 90°. These tabs are located on the sides and
3–2
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 3: INSTALLATIONINSTALLATION
bottom of the case and appear as shown in the illustration. After bending all tabs, the case
will be securely mounted so that its relay can be inserted. The SR unit is now ready for
panel wiring.
FIGURE 3–4: Case mounting
3.1.4
Unit Withdrawal and Insertion
TURN OFF CONTROL POWER BEFORE DRAWING OUT OR RE-INSERTING THE RELAY TO
PREVENT MALOPERATION!
If an attempt is made to install a unit into a non-matching case, the mechanical key will
prevent full insertion of the unit. Do not apply strong force in the following step or damage
may result.
To remove the unit from the case:
1.
Open the cover by pulling the upper or lower corner of the right side, which will rotate
about the hinges on the left.
2.
Release the locking latch, located below the locking handle, by pressing upward on
the latch with the tip of a screwdriver.
FIGURE 3–5: Press latch to disengage handle
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
3–3
INSTALLATIONCHAPTER 3: INSTALLATION
3.
Grasp the locking handle in the center and pull firmly, rotating the handle up from the
bottom of the unit until movement ceases.
FIGURE 3–6: Rotate handle to stop position
4.
Once the handle is released from the locking mechanism, the unit can freely slide out
of the case when pulled by the handle. It may sometimes be necessary to adjust the
handle position slightly to free the unit.
FIGURE 3–7: Slide unit out of case
To insert the unit into the case:
3–4
1.
Raise the locking handle to the highest position.
2.
Hold the unit immediately in front of the case and align the rolling guide pins (near the
hinges of the locking handle) to the guide slots on either side of the case.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 3: INSTALLATIONINSTALLATION
3.
Slide the unit into the case until the guide pins on the unit have engaged the guide
slots on either side of the case.
4.
Grasp the locking handle from the center and press down firmly, rotating the handle
from the raised position toward the bottom of the unit.
5.
When the unit is fully inserted, the latch will be heard to click, locking the handle in the
final position.
To prevent unauthorized removal of the drawout unit, a wire lead seal can be installed in
the slot provided on the handle as shown below. With this seal in place, the drawout unit
cannot be removed. A passcode or setpoint access jumper can be used to prevent entry of
setpoints but still allow monitoring of actual values. If access to the front panel controls
must be restricted, a separate seal can be installed on the outside of the cover to prevent it
from being opened.
FIGURE 3–8: Drawout unit seal
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
3–5
INSTALLATIONCHAPTER 3: INSTALLATION
3.1.5
Ethernet connection
If using the 745 with the Ethernet 10Base-T option, ensure that the network cable is
disconnected from the rear RJ45 connector before removing the unit from the case. This
prevents any damage to the connector.
The unit may also be removed from the case with the network cable connector still
attached to the rear RJ45 connector, provided that there is at least 16 inches of network
cable available when removing the unit from the case. This extra length allows the network
cable to be disconnected from the RJ45 connector from the front of the switchgear panel.
Once disconnected, the cable can be left hanging safely outside the case for re-inserting
the unit back into the case.
The unit may then be re-inserted by first connecting the network cable to the units' rear
RJ45 connector (see step 3 of Unit Withdrawal and Insertion on page 3–3).
Ensure that the network cable does not get caught inside the case while sliding in the
unit. This may interfere with proper insertion to the case terminal blocks and damage
the cable.
FIGURE 3–9: Ethernet cable connection
To ensure optimal response from the relay, the typical connection timeout should be set as
indicated in the following table:
TCP/IP sessions
3–6
Timeout setting
up to 2
2 seconds
up to 4
3 seconds
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 3: INSTALLATIONINSTALLATION
3.2
Typical Wiring
3.2.1
Description
The 745 contains numerous built-in features that allow for a broad range of applications.
As such, it is not possible to present connections for all possible schemes. The information
in this section covers the important aspects of interconnections, in the general areas of
instrument transformer inputs, other inputs, outputs, communications, and grounding.
3.2.2
Rear Terminal Layout
FIGURE 3–10: Rear terminal layout
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
3–7
INSTALLATIONCHAPTER 3: INSTALLATION
Table 3–1: Rear terminal assignments (Sheet 1 of 2)
Term.
Description
Term.
Analog interface
Outputs and ground CT N2
A1
Analog input +
E1
Output 1: solid state trip (+)
A2
Analog input –
E2
Output 2: trip relay (NO)
A3
Tap position (+)
E3
Output 3: trip relay (NO)
A4
Tap position (–)
E4
Output 4: trip relay (NO)
A5
Analog output (common)
E5
Output 5: trip relay (NO)
A6
Analog output 1 (+)
E6
Output 6: auxiliary relay (NO)
A7
Analog output 2 (+)
E7
Output 6: auxiliary relay (NC)
A8
Analog output 3 (+)
E8
Output 7: auxiliary relay (NO)
A9
Analog output 4 (+)
E9
Output 8: auxiliary relay (NO)
A10
Analog output 5 (+)
E10
Output 8: auxiliary relay (NC)
A11
Analog output 6 (+)
E11
Output 9: service relay (common)
A12
Analog output 7 (+)
E12
Ground: winding 2/3 CT
Communications and RTD inputs
Outputs and ground CT N2
B1
Computer RS485 (+) / RS422 (Rx+)
F1
Output 1: solid state trip (–)
B2
Computer RS485 (–) / RS422 (Rx–)
F2
Output 2: trip relay (common)
B3
Computer RS485/RS422 (common)
F3
Output 3: trip relay (common)
B4
RS422 (Tx+)
F4
Output 4: trip relay (common)
B5
RS422 (Tx–)
F5
Output 5: trip relay (common)
B6
External RS485 (+)
F6
Output 6: auxiliary relay (common)
B7
External RS485 (–)
F7
Output 7: auxiliary relay (NO)
B8
IRIG-B +
F8
Output 7: auxiliary relay (NC)
B9
IRIG-B –
F9
Output 8: auxiliary relay (common)
B10
RTD 1 hot
F10
Output 9: service relay (NO)
B11
RTD 1 compensation
F11
Output 9: service relay (NC)
B12
RTD 1 return
F12
Ground: winding 2/3 CT „
Logic inputs 9 to 16 and VT input
CT inputs and 745 grounding
C1
Logic input 9 (+)
G1
Phase A: winding 1 CT
C2
Logic input 10 (+)
G2
Phase B: winding 1 CT
C3
Logic input 11 (+)
G3
Phase C: winding 1 CT
C4
Logic input 12 (+)
G4
Phase A: winding 2 CT
C5
Logic input 13 (+)
G5
Phase B: winding 2 CT
C6
Logic input 14 (+)
G6
Phase C: winding 2 CT
C7
Logic input 15 (+)
G7
Phase A: winding 3 CT
C8
Logic input 16 (+)
G8
Phase B: winding 3 CT
C9
Reserved
G9
Phase C: winding 3 CT
C10
Reserved
G10
Ground: winding 1/2 CT
C11
VT input „
G11
745 filter ground
C12
VT input
G12
745 safety ground
Logic inputs 1 to 8 and dedicated inputs
3–8
Description
CT and VT inputs / power
D1
Logic input 1 (+)
H1
Phase A: winding 1 CT „
D2
Logic input 2 (+)
H2
Phase B: winding 1 CT „
D3
Logic input 3 (+)
H3
Phase C: winding 1 CT „
D4
Logic input 4 (+)
H4
Phase A: winding 2 CT „
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 3: INSTALLATIONINSTALLATION
Table 3–1: Rear terminal assignments (Sheet 2 of 2)
Term.
Note
Description
Term.
Description
D5
Logic input 5 (+)
H5
Phase B: winding 2 CT „
D6
Logic input 6 (+)
H6
Phase C: winding 2 CT „
D7
Logic input 7 (+)
H7
Phase A: winding 3 CT „
D8
Logic input 8 (+)
H8
Phase B: winding 3 CT „
D9
Setpoint access (+)
H9
Phase C: winding 3 CT „
D10
Setpoint access (–)
H10
Ground: winding 1/2 CT „
D11
Logic power out (+)
H11
Control power (–)
D12
Logic power out (–)
H12
Control power (+)
The „ symbol indicates the high side of CT and VT terminals
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
3–9
INSTALLATIONCHAPTER 3: INSTALLATION
3.2.3
Wiring Diagrams
MULTILIN
FIGURE 3–11: Typical wiring for two-winding transformer
Note
3–10
Since the relay takes one voltage input, power and var metering is not accurate for
unbalanced conditions. In addition, depending on which winding the VT is on, the power
flows and vars displayed may be opposite in direction to the actual system flow; e.g. in the
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 3: INSTALLATIONINSTALLATION
case of a generator step-up transformer, depending on the relay winding assignments and
which side of the transformer the VT is connected to, the power may be negative when the
generator is producing positive MW. This can be corrected by reversing the voltage input
into C11 and C12.
MULTILIN
FIGURE 3–12: Typical wiring for three-winding transformer
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
3–11
INSTALLATIONCHAPTER 3: INSTALLATION
3.2.4
Phase Sequence and Transformer Polarity
For the correct operation of many relay features, the phase sequence and instrument
transformer polarities shown on the typical wiring diagram must be followed. Note the
markings shown with all instrument transformer connections. When the connections
adhere to this drawing, the relay will operate properly.
3.2.5
Current Transformer Inputs
The 745 has eight or eleven channels for AC current inputs, each with an isolating
transformer and an automatic shorting mechanism that acts when the relay is withdrawn
from its case. There are no internal ground connections on the current inputs. Current
transformers with 1 to 50000 A primaries may be used.
The SR-745 Relay has inputs for either two or three transformer windings (specified at the
time of ordering) and for two ground current inputs, G1/2 and G2/3. Refer to the wiring
diagrams below for details. Upon transformer type selection, the ground inputs are
associated to one or another winding under the following conditions:
1.
The ground input settings will be shown in the winding configuration for the
transformer type selections associated with a ground input.
2.
When a 2-winding transformer is selected, ground inputs are enabled, on both, and
are pre-assigned. G1/2 is assigned to winding 1, and G2/3 is assigned to winding 2.
3.
When a 3-winding transformer is selected, both ground inputs are enabled, and are
associated with the windings via the following rules (see table 3-2):
• The 50G function is enabled for all connection scenarios (ie: delta and wye).
• Flexibility is provided to the user in the case of a 3-winding transformer, so the user
can assign G1/2 and G2/3 Ground inputs to any two of the three available
windings.
4.
Robustness, built into the relay, will not allow the user to assign a ground input to
more than one winding. In the EnerVista 745 software, a flag informs the user with the
text: "Ground CT Input ’G#/#’ has already been selected for another winding". On the
relay firmware, "Input Function is Already Assigned" text is displayed.
The following table shows the ground inputs use for typical transformer setups:
Table 3–2: Typical Ground Input Connections
TRANSFORMER WINDING CONNECTIONS
3–12
WINDING ASSOCIATED WITH
GROUND INPUT
WINDING 1
WINDING 2
WINDING 3
G1/2
G2/3
Wye
Wye
--
Winding 1
Winding 2
Delta
Delta
--
Winding 1
Winding 2
Delta
Wye
--
Winding 1
Winding 2
Delta
Delta
--
Winding 1
Winding 2
Wye
Zig-Zag
--
Winding 1
Winding 2
Delta
Zig-Zag
--
Winding 1
Winding 2
Wye
Wye
Wye
Winding 1
Winding 2
Wye
Wye
Wye
Winding 2
Winding 3
Wye
Wye
Wye
Winding 3
Winding 1
Wye
Wye
Wye
Winding 2
Winding 1
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 3: INSTALLATIONINSTALLATION
Table 3–2: Typical Ground Input Connections
TRANSFORMER WINDING CONNECTIONS
WINDING ASSOCIATED WITH
GROUND INPUT
WINDING 1
WINDING 2
WINDING 3
G1/2
G2/3
Wye
Wye
Wye
Winding 3
Winding 2
Wye
Wye
Wye
Winding 1
Winding 3
Wye
Wye
Delta
Winding 1
Winding 2
Wye
Wye
Delta
Winding 1
Winding 3
Wye
Wye
Delta
Winding 2
Winding 3
Wye
Wye
Delta
Winding 2
Winding 1
Wye
Wye
Delta
Winding 3
Winding 1
Wye
Wye
Delta
Winding 3
Winding 2
Wye
Delta
Wye
Winding 1
Winding 3
Wye
Delta
Wye
Winding 1
Winding 2
Wye
Delta
Wye
Winding 2
Winding 3
Wye
Delta
Wye
Winding 3
Winding 1
Wye
Delta
Wye
Winding 2
Winding 1
Wye
Delta
Wye
Winding 3
Winding 2
Wye
Delta
Delta
Winding 1
Winding 2
Wye
Delta
Delta
Winding 1
Winding 3
Wye
Delta
Delta
Winding 2
Winding 3
Wye
Delta
Delta
Winding 2
Winding 1
Wye
Delta
Delta
Winding 3
Winding 1
Wye
Delta
Delta
Winding 3
Winding 2
Delta
Wye
Wye
Winding 1
Winding 2
Delta
Wye
Wye
Winding 1
Winding 3
Delta
Wye
Wye
Winding 2
Winding 3
Delta
Wye
Wye
Winding 2
Winding 1
Delta
Wye
Wye
Winding 3
Winding 1
Delta
Wye
Wye
Winding 3
Winding 2
Delta
Wye
Delta
Winding 1
Winding 2
Delta
Wye
Delta
Winding 1
Winding 3
Delta
Wye
Delta
Winding 2
Winding 3
Delta
Wye
Delta
Winding 2
Winding 1
Delta
Wye
Delta
Winding 3
Winding 1
Delta
Wye
Delta
Winding 3
Winding 2
Delta
Delta
Delta
Winding 1
Winding 2
Delta
Delta
Delta
Winding 1
Winding 3
Delta
Delta
Delta
Winding 2
Winding 3
Delta
Delta
Delta
Winding 2
Winding 1
Delta
Delta
Delta
Winding 3
Winding 1
Delta
Delta
Delta
Winding 3
Winding 2
Delta
Delta
Wye
Winding 1
Winding 2
Delta
Delta
Wye
Winding 1
Winding 3
Delta
Delta
Wye
Winding 2
Winding 3
Delta
Delta
Wye
Winding 2
Winding 1
Delta
Delta
Wye
Winding 3
Winding 1
Delta
Delta
Wye
Winding 3
Winding 2
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
3–13
INSTALLATIONCHAPTER 3: INSTALLATION
Verify that the relay’s nominal current of 1 A or 5 A matches the secondary rating of the
connected CTs. Unmatched CTs may result in equipment damage or inadequate
protection.
The exact placement of a zero-sequence CT so that ground fault current will be detected is
shown below. Twisted pair cabling on the zero-sequence CT is recommended.
IMPORTANT: The relay will correctly measure up to 46 times the current input nominal
rating. Time overcurrent curves become horizontal lines for currents above the 46 × CT
rating.
Note
FIGURE 3–13: Zero-sequence (core balance) CT installation
3.2.6
AC Voltage Input
The 745 has one voltage divider type input for AC voltages. There are no internal fuses or
ground connections. Voltage transformers up to a maximum 5000:1 ratio may be used.
The nominal secondary voltage must be in the 60 to 120 V range.
3.2.7
Logic Inputs
External contacts can be connected to the 16 logic inputs. As shown, these contacts can
be either dry or wet. It is also possible to use a combination of both contact types.
A dry contact has one side connected to terminal D11. This is the +32 V DC voltage rail. The
other side is connected to the required logic input terminal. When a dry contact closes, a
2.2 mA current flows through the associated circuit.
A wet contact has one side connected to the positive terminal of an external DC power
supply. The other side is connected to the required logic input terminal. In addition, the
negative side of the external source must be connected to the relay DC negative rail at
terminal D12. The maximum external source voltage for this arrangement is 300 V DC.
Correct polarity must be observed for all logic input connections or equipment damage
may result.
3–14
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 3: INSTALLATIONINSTALLATION
FIGURE 3–14: Dry and wet contact connections
3.2.8
Control Power
The label found on the left side of the relay specifies its order code or model number. The
installed power supply operating range will be one of the following.
LO: 25 to 60 V DC or 20 to 48 V AC
HI: 88 to 300 V DC or 70 to 265 V AC
Ensure the applied control voltage matches the requirements of the relay’s switching
power supply. For example, the HI power supply will work with any DC voltage from 88 to
300 V, or any AC voltage from 70 to 265 V. The internal fuse may blow if the applied voltage
exceeds this range.
Control power supplied to the relay must match the installed power supply range. If the
applied voltage does not match, damage to the unit may occur.
FIGURE 3–15: Control power connection
Extensive filtering and transient protection are built into the 745 to ensure proper
operation in harsh industrial environments. Transient energy must be conducted back to
the source through the filter ground terminal. A separate safety ground terminal is
provided for dielectric strength (hi-pot) testing.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
3–15
INSTALLATIONCHAPTER 3: INSTALLATION
3.2.9
Analog Input
Terminals A1 (+) and A2 (–) are provided for the input of a current signal, from one of the
following: 0 to 1 mA, 0 to 5 mA, 0 to 20 mA, or 4 to 20 mA transducer outputs. This current
signal can represent any external quantity, such as temperature, current or voltage. Be
sure to observe polarity markings for correct operation. Both terminals are clamped to
within 36 volts of ground with surge protection. As such, common mode voltages should
not exceed this limit. Shielded wire, with only one end of the shield grounded, is
recommended to minimize noise effects. The A2 (–) terminal must be connected to the A5
(analog output common) terminal at the 745.
3.2.10 Tap Position Input
Terminals A3 (+) and A4 (–) are provided to monitor the position of an onload tap changer
from a stepped-resistance position indicator device. Terminal A3 is connected internally to
a 4.3 mA current source. This current is used to measure the value of the external
resistance. The 745 uses the measured resistance value to calculate the tap position. See
Dynamic CT Ratio Mismatch Correction on page 5–6 for more details on the tap position
input.
The maximum total resistance the tap changer input can measure is 5.1 kΩ. For example,
the maximum resistance increment per tap for a 33-position tap changer should not
exceed 151 Ω.
3.2.11 RTD Driver/Sensor
Terminals B10 (RTD hot), B11 (RTD compensation) and B12 (RTD return) provide for the
connection of various types of RTD devices. This connection may be made using two or
three wires to the RTD. Terminal B10 is connected internally to a 5 mA current source for
energizing the RTD. Terminal B11 is connected internally to a 5 mA current source for the
purpose of cancelling out the resistance of the wires connecting the RTD to the 745.
Terminal B12 is the return path for the two current sources.
In the three-wire connection scheme, the connection from terminal B11 to B12 is made at
the RTD. The three-wire connection scheme compensates for the resistance of the wiring
between the 745 and the RTD.
In the two-wire connection scheme, the connection from terminal B11 to B12 is made at
the terminal block on the rear of the 745. This connection must not be omitted. The twowire connection scheme does not compensate for the resistance of the wiring between the
745 and the RTD.
3.2.12 Output Relays
Eight output relays are provided with the 745. Output relays 2 through 5 have form-A
contacts while output relays 6 to 8 and the self-test relay, have form-C contacts. Since
output relays 2 to 5 are intended for operating a breaker trip coil, the form-A contacts have
higher current ratings than the form-C contacts. Note that the operating mode of the selftest relay is fixed, while the other relays can be assigned through the Protection Elements
menu, or programmed by the user via the FlexLogic™ feature.
3–16
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 3: INSTALLATIONINSTALLATION
3.2.13 Solid State Trip Output
A high-speed solid state (SCR) output is also provided. This output is intended for
applications where it is necessary to key a communications channel.
3.2.14 Analog Outputs
The 745 provides 7 analog output channels whose full scale range can be set to one of the
following ranges: 0 to 1 mA; 0 to 5 mA; 0 to 10 mA; 0 to 20 mA; and 4 to 20 mA. Each analog
output channel can be programmed to represent one of the parameters measured by the
relay. For details, see Analog Outputs 1 to 7 on page 5–43.
As shown in the typical wiring diagram, the analog output signals originate from Terminals
A6 to A12 and share A5 as a common return. Output signals are internally isolated and
allow connection to devices which sit at a different ground potential. Each analog output
terminal is clamped to within 36 V of ground. To minimize the effects of noise, external
connections should be made with shielded cable and only one end of the shield should be
grounded.
If a voltage output is required, a burden resistor must be connected at the input of the
external measuring device. Ignoring the input impedance, the burden resistance is:
V FULL-SCALE
R LOAD = ---------------------------I MAX
(EQ 3.1)
If a 5 V full scale output is required with a 0 to 1 mA output channel, RLOAD = 5 V / 0.001 A =
5 KΩ. Similarly, for a 0 to 5 mA channel this resistor would be 1 KΩ; for a 0 to 10 mA
channel, this resistor would be 500 Ω; and for a 4 to 20 mA channel this resistor would be
250 Ω.
FIGURE 3–16: Analog output connection
3.2.15 RS485/RS422 Communications
The 745 provides the user with two rear communication ports which may be used
simultaneously. Both implement a subset of the AEG Modicon Modbus protocol as outlined
in publication GEK-106636A: 745 Communications Guide.
The COM1 port can be used in the two-wire RS485 mode or the four-wire RS422 mode, but
will not operate in both modes at the same time. In RS485 mode, data transmission and
reception are accomplished over a single twisted pair with transmit and receive data
alternating over the same two wires. These wires should be connected to the terminals
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
3–17
INSTALLATIONCHAPTER 3: INSTALLATION
marked RS485. The RS422 mode uses the COM1 terminals designated as RS485 for receive
lines, and the COM1 terminals designated as RS422 for transmit lines. The COM2 port is
intended for the two wire RS485 mode only. Through the use of these ports, continuous
monitoring and control from a remote computer, SCADA system or PLC is possible.
To minimize errors from noise, the use of shielded twisted-pair wire is recommended.
Correct polarity should also be observed. For instance, the relays must be connected with
all B1 terminals (labeled COM1 RS485+) connected together, and all B2 terminals (labeled
COM1 RS485–) connected together. Terminal B3 (labeled COM1 RS485 COM) should be
connected to the common wire inside the shield. To avoid loop currents, the shield should
be grounded at one point only. Each relay should also be daisy-chained to the next in the
link. A maximum of 32 relays can be connected in this manner without exceeding driver
capability. For larger systems, additional serial channels must be added. It is also possible
to use commercially available repeaters to include more than 32 relays on a single
channel. Star or stub connections should be avoided entirely.
Lightning strikes and ground surge currents can cause large momentary voltage
differences between remote ends of the communication link. For this reason, surge
protection devices are internally provided at both communication ports. An isolated power
supply with an optocoupled data interface also acts to reduce noise coupling. To ensure
maximum reliability, all equipment should have similar transient protection devices
installed.
FIGURE 3–17: RS485 wiring
3–18
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 3: INSTALLATIONINSTALLATION
FIGURE 3–18: RS422 wiring
3.2.16 RS232 Front Panel Program Port
A 9 pin RS232C serial port is located on the front panel for programming through a PC. This
port uses the same Modbus protocol as the two rear ports. The EnerVista 745 Setup
software required to use this interface is included with the relay. Cabling for the RS232 port
is shown below for both 9 pin and 25 pin connectors.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
3–19
INSTALLATIONCHAPTER 3: INSTALLATION
FIGURE 3–19: RS232 Wiring
3.2.17 IRIG-B
IRIG-B is a standard time code format that allows stamping of events to be synchronized
among connected devices within 1 millisecond. The IRIG time code formats are serial,
width-modulated codes which can be either DC level shifted or amplitude modulated (AM).
Third party equipment is available for generating the IRIG-B signal; this equipment may use
a GPS satellite system to obtain the time reference so that devices at different geographic
locations can also be synchronized.
GPS SATELLITE SYSTEM
GPS CONNECTION
OPTIONAL
IRIG-B
TIME CODE
GENERATOR
(DC SHIFT OR
AMPLITUDE MODULATED
SIGNAL CAN BE USED)
745 RELAY
RG58/59 COAXIAL CABLE
+
B8
IRIG-B(+)
–
B9
IRIG-B(–)
RECEIVER
814823A1.CDR
TO OTHER DEVICES
FIGURE 3–20: IRIG-B function
3.2.18 Dielectric Strength
Dielectric strength test was performed on the 745 relay at the manufacturer. It is not
necessary to perform this test again at the customer site. However, if you wish to perform
this test, follow instructions outlined in Dielectric Strength Testing on page 7–6.
3–20
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 3: INSTALLATIONINSTALLATION
Note
No special ventilation requirements need to be observed during the installation of the
unit. The unit does not have to be cleaned.
Hazard may result if the product is not used for its intended purpose.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
3–21
INSTALLATIONCHAPTER 3: INSTALLATION
3–22
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
GE Consumer & Industrial
Multilin
745 Transformer Protection
System
Chapter 4: Interfaces
Interfaces
4.1
Hardware Interface
4.1.1
Front Panel
The front panel provides a local operator interface with a 40-character liquid crystal
display, LED status indicators, control keys, and program port. The display and status
indicators update alarm and status information automatically. The control keys are used
to select the appropriate message for entering setpoints or displaying measured values.
The RS232 program port is also provided for connection with a computer running the
EnerVista 745 Setup software.
FIGURE 4–1: 745 front panel view
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
4–1
INTERFACESCHAPTER 4: INTERFACES
4.1.2
Display
All messages are displayed in English on the 40-character liquid crystal display, which is
backlit for visibility under varied lighting conditions. When the keypad and display are not
actively being used, the screen sequentially displays up to 30 user-selected default
messages providing system information. These messages appear after a time of inactivity
that is programmable by the user. Pressing any key after default messages have appeared
will return the display to the last message displayed before the default messages
appeared. Trip and alarm condition messages automatically override default messages. All
display pixels are illuminated briefly during power up self-testing, and can be energized by
pressing any key when no trips or alarms are active.
4.1.3
LEDs
Front panel indicators are grouped in three columns: Relay Status, which provides
information about the state of the 745; System Status, which provides information about
the state of the transformer and the power system; and Output Status, which provides
details about abnormal conditions that have been detected. The color of each indicator
conveys information about its importance:
GREEN (G): indicates a general condition
AMBER (A): indicates an alert condition
RED (R): indicates a serious alarm or warning
4.1.4
LED Indicators
4.1.4.1 745 Status
•
4–2
RELAY IN SERVICE: The In Service LED is on when relay protection is operational. The
indicator is on only if all of the following conditions are met:
–
The S1 745 SETUP ZV INSTALLATION ZV 745 SETPOINTS setpoint is set to
“Programmed”.
–
The S6 TESTING Z OUTPUT RELAYS Z FORCE OUTPUT RELAYS FUNCTION setpoint is
set to “Disabled”.
–
The S6 TESTING ZV SIMULATION Z SIMULATION SETUP Z SIMULATION FUNCTION
setpoint is set to “Disabled”.
–
No self-test errors which have an effect on protection have been detected.
–
Code programming mode is inactive.
–
Factory service mode is disabled.
•
SELF-TEST ERROR: The Self-Test Error LED is on when any of the self-diagnostic tests,
performed either at power-on or in the background during normal operation, has
detected a problem with the relay.
•
TEST MODE: The Test Mode LED indicator is on when any of the 745 testing features
has been enabled. The indicator is on if any of the following conditions are met:
–
The S6 TESTING Z OUTPUT RELAYS Z FORCE OUTPUT RELAYS FUNCTION setpoint is
set to “Enabled”.
–
The S6 TESTING ZV ANALOG OUTPUTS Z FORCE ANALOG OUTPUTS FUNCTION
setpoint is “Enabled”.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: INTERFACESINTERFACES
–
The S6 TESTING ZV SIMULATION Z SIMULATION SETUP Z SIMULATION FUNCTION
setpoint is set to “Prefault Mode”, “Fault Mode”, or “Playback Mode”.
–
Factory service mode is enabled.
•
DIFFERENTIAL BLOCKED: The Differential Blocked LED is on when the restrained
differential protection feature is enabled but is being blocked from operating by any of
the harmonic inhibit features. The indicator is on if the harmonic inhibit element is
blocking any phase (see Harmonic inhibit on page 5–52).
•
LOCAL: The Local LED indicator is on when the 745 is in local mode, i.e. the front panel
RESET key is operational.
•
MESSAGE: The Message LED indicator is on when any element has picked up,
operated, or is now in a latched state waiting to be reset. With this indicator on, the
front panel display is sequentially displaying information about each element that has
detected an abnormal condition.
4.1.4.2 System Status Indicators
•
TRANSFORMER DE-ENERGIZED: The Transformer De-Energized LED indicator is on
when the energization inhibit feature has detected that the transformer is deenergized. The indicator is on if the Energization Inhibit feature is detecting the
transformer as de-energized
•
TRANSFORMER OVERLOAD: The Transformer Overload LED indicator is on when the
Transformer Overload element has operated.
•
LOAD-LIMIT REDUCED: The Load-Limit Reduced LED indicator is on when the
adaptive harmonic factor correction feature is detecting enough harmonic content to
reduce the load rating of the transformer. The indicator is on if S2 SYSTEM SETUP ZV
HARMONICS Z HARMONIC DERATING ESTIMATION is “Enabled” and the harmonic
derating function is below 0.96.
•
SETPOINT GROUP 1(4): These indicators reflect the currently active setpoint group.
The indicators flash when the corresponding setpoint group is being edited.
4.1.4.3 Output Status Indicators
•
TRIP: The Trip LED is on when any output relay selected to be of the Trip type has
operated.
•
ALARM: The Alarm LED is on when any output relay selected to be of the Alarm type
has operated.
•
PICKUP: The Pickup LED is on when any element has picked up. With this indicator on,
the front panel display is sequentially displaying information about each element that
has picked up.
•
PHASE A (C): The Phase A(C) LEDs are on when phase A(C) is involved in the condition
detected by any element that has picked up, operated, or is now in a latched state
waiting to be reset.
•
Ground: The Ground LED is on when ground is involved in the condition detected by
any element that has picked up, operated, or is now in a latched state waiting to be
reset.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
4–3
INTERFACESCHAPTER 4: INTERFACES
4.1.5
Program Port
Use the front panel program port for RS232 communications with the 745. As described in
RS232 Front Panel Program Port on page 3–19, all that is required is a connection between
the relay and a computer running EnerVista 745 Setup. For continuous monitoring of
multiple relays, use the COM1 RS485/RS422 port or the COM2 RS485 port.
4.1.6
Keypad
4.1.6.1 Description
The 745 display messages are organized into main menus, pages, and sub-pages. There
are three main menus labeled setpoints, actual values, and target messages.
Pressing the MENU key followed by the MESSAGE DOWN key scrolls through the three main
menu headers, which appear in sequence as follows:
SETPOINTS
[ Z]
ACTUAL VALUES
[ Z]
TARGET MESSAGES [Z]
Pressing the MESSAGE RIGHT or ENTER key from these main menu pages will display the
corresponding menu page. Use the MESSAGE keys to scroll through the page headers.
When the display shows SETPOINTS, pressing the MESSAGE RIGHT or ENTER key will display
the page headers of programmable parameters (referred to as setpoints in the manual).
When the display shows ACTUAL VALUES, pressing the MESSAGE RIGHT or ENTER key
displays the page headers of measured parameters (referred to as actual values in the
manual). When the display shows TARGET MESSAGES, pressing the MESSAGE RIGHT or
ENTER key displays the page headers of event messages or alarm conditions.
Each page is broken down further into logical sub-pages. The MESSAGE keys are used to
navigate through the sub-pages. A summary of the setpoints and actual values can be
found in the chapters 5 and 6, respectively.
The ENTER key is dual purpose. It is used to enter the sub-pages and to store altered
setpoint values into memory to complete the change. The MESSAGE RIGHT key can also be
used to enter sub-pages but not to store altered setpoints.
The ESCAPE key is also dual purpose. It is used to exit the sub-pages and to cancel a
setpoint change. The MESSAGE LEFT key can also be used to exit sub-pages and to cancel
setpoint changes.
The VALUE keys are used to scroll through the possible choices of an enumerated setpoint.
They also decrement and increment numerical setpoints. Numerical setpoints may also be
entered through the numeric keypad.
The RESET key resets any latched conditions that are not presently active. This includes
resetting latched output relays, latched Trip LEDs, breaker operation failure, and trip coil
failure.
4–4
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: INTERFACESINTERFACES
The MESSAGE keys scroll through any active conditions in the relay. Diagnostic messages
are displayed indicating the state of protection and monitoring elements that are picked
up, operating, or latched. When the Message LED is on, there are messages to be viewed
with the MENU key by selecting target messages as described earlier.
4.1.6.2 Entering alphanumeric text
Text setpoints have data values that are fixed in length but user-defined in character. They
may be comprised of upper case letters, lower case letters, numerals, and a selection of
special characters. The editing and storing of a text value is accomplished with the use of
the decimal, VALUE, and ENTER keys.
1.
Move to message S3 LOGIC INPUTS Z LOGIC INPUTS Z LOGIC INPUT 1 Z INPUT 1
FUNCTION, and scrolling with the VALUE keys, select “Enabled”. The relay will display
the following message:
INPUT 1 FUNCTION:
Enabled
2.
Press the MESSAGE DOWN key twice to view the INPUT NAME setpoint. The name of
this user-defined input will be changed in this example from the generic “Logic Input
1” to something more descriptive.
3.
If an application is to be using the relay as a transformer monitor, it may be more
informative to rename this input “Tx. Monitor”. Press decimal to enter the text editing
mode. The first character will appear underlined as follows:
INPUT 1 NAME:
Logic Input 1
4.
Press the VALUE keys until the character “T” is displayed in the first position. Now press
the decimal key to store the character and advance the cursor to the next position.
Change the second character to a “x” in the same manner. Continue entering
characters in this way until all characters of the text “Tx. Monitor” are entered. Note
that a space is selected like a character. If a character is entered incorrectly, press the
decimal key repeatedly until the cursor returns to the position of the error. Re-enter
the character as required. Once complete, press the ENTER key to remove the solid
cursor and view the result. Once a character is entered, by pressing the ENTER key, it is
automatically saved in Flash Memory, as a new setpoint.
INPUT 1 NAME:
Tx. Monitor
5.
4.1.7
The 745 does not have '+' or '–' keys. Negative numbers may be entered in one of two
manners.
–
Immediately pressing one of the VALUE keys causes the setpoint to scroll through
its range including any negative numbers.
–
After entering at least one digit of a numeric setpoint value, pressing the VALUE
keys changes the sign of the value where applicable.
Setpoint Entry
To store any setpoints, terminals C1 and C2 (access terminals) must be shorted (a
keyswitch may be used for security). There is also a setpoint passcode feature that restricts
access to setpoints. The passcode must be entered to allow the changing of setpoint
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
4–5
INTERFACESCHAPTER 4: INTERFACES
values. A passcode of “0” effectively turns off the passcode feature - in this case only the
access jumper is required for changing setpoints. If no key is pressed for 5 minutes, access
to setpoint values will be restricted until the passcode is entered again. To prevent setpoint
access before the 5 minutes expires, the unit may be turned off and back on, the access
jumper may be removed, or the SETPOINT ACCESS setpoint may be changed to
“Restricted”. The passcode cannot be entered until terminals C1 and C2 (access terminals)
are shorted. When setpoint access is allowed, the Setpoint Access LED indicator on the
front of the 745 will be lit.
Setpoint changes take effect immediately, even when transformer is running. However,
changing setpoints while the transformer is running is not recommended as any mistake
may cause a nuisance trip.
The following procedure may be used to access and alter setpoints. This specific example
refers to entering a valid passcode to allow access to setpoints if the passcode was “745”.
1.
Press the MENU key to access the header of each menu, which will be displayed in the
following sequence:
SETPOINTS
[ Z]
[ Z]
ACTUAL VALUES
TARGET MESSAGES [Z]
2.
Press the MENU key until the display shows the header of the setpoints menu, then
press the MESSAGE RIGHT or ENTER key to display the header for the first setpoints
page. The set point pages are numbered, have an 'S' prefix for easy identification and
have a name which gives a general idea of the settings available in that page.
Pressing the MESSAGE keys will scroll through all the available setpoint page headers.
Setpoint page headers look as follows:
„ SETPOINTS
[ Z]
S1 745 SETUP
3.
To enter a given setpoints page, press the MESSAGE RIGHT or ENTER key. Press the
MESSAGE keys to scroll through sub-page headers until the required message is
reached. The end of a page is indicated by the message END OF PAGE. The beginning
of a page is indicated by the message TOP OF PAGE.
4.
Each page is broken further into subgroups. Press MESSAGE UP or DOWN to cycle
through subgroups until the desired subgroup appears on the screen. Press the
MESSAGE RIGHT or ENTER key to enter a subgroup.
„ PASSCODE
5.
[ Z]
Each sub-group has one or more associated setpoint messages. Press the MESSAGE
UP or DOWN keys to scroll through setpoint messages until the desired message
appears.
ENTER PASSCODE
FOR ACCESS:
4–6
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: INTERFACESINTERFACES
6.
The majority of setpoints are changed by pressing the VALUE keys until the desired
value appears, and then pressing ENTER. Numeric setpoints may also be entered
through the numeric keys (including decimals). If the entered setpoint is out of range,
the original setpoint value reappears. If the entered setpoint is out of step, an adjusted
value will be stored (e.g. 101 for a setpoint that steps 95, 100, 105 is stored as 100). If a
mistake is made entering the new value, pressing ESCAPE returns the setpoint to its
original value. Text editing is a special case described in detail in Entering
alphanumeric text on page 4–5. Each time a new setpoint is successfully stored, a
message will flash on the display stating NEW SETPOINT HAS BEEN STORED.
7.
Press the 4, 8, and 9 keys, then press ENTER. The following flash message is displayed:
NEW SETPOINT
HAS BEEN STORED
and the display returns to:
SETPOINT ACCESS:
PERMITTED
8.
4.1.8
Press ESCAPE or MESSAGE LEFT to exit the subgroup. Pressing ESCAPE or MESSAGE
LEFT numerous times will always return the cursor to the top of the page.
Diagnostic Messages
Diagnostic messages are automatically displayed for any active conditions in the relay
such as trips, alarms, or asserted logic inputs. These messages provide a summary of the
present state of the relay. The Message LED flashes when there are diagnostic messages
available; press the MENU key until the relay displays TARGET MESSAGES, then press the
MESSAGE RIGHT key, followed by the MESSAGE DOWN key, to scroll through the messages.
4.1.9
Flash Messages
Flash messages are warning, error, or general information messages displayed in response
to certain key presses. The length of time these messages remain displayed can be
programmed in S1 745 SETUP ZV PREFERENCES ZV DEFAULT MESSAGE CYCLE TIME. The
factory default flash message time is 4 seconds. For additional information and a complete
list of flash messages, refer to Flash Messages on page 6–27.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
4–7
INTERFACESCHAPTER 4: INTERFACES
4.2
EnerVista Software Interface
4.2.1
Overview
The front panel provides local operator interface with a liquid crystal display. The EnerVista
745 Setup software provides a graphical user interface (GUI) as one of two human
interfaces to a 745 device. The alternate human interface is implemented via the device's
faceplate keypad and display (see the first section in this chapter).
The EnerVista 745 Setup software provides a single facility to configure, monitor, maintain,
and trouble-shoot the operation of relay functions, connected over serial communication
networks. It can be used while disconnected (i.e. off-line) or connected (i.e. on-line) to a 745
device. In off-line mode, settings files can be created for eventual downloading to the
device. In on-line mode, you can communicate with the device in real-time.
This no-charge software, provided with every 745 relay, can be run from any computer
supporting Microsoft Windows® 95 or higher. This chapter provides a summary of the
basic EnerVista 745 Setup software interface features. The EnerVista 745 Setup help file
provides details for getting started and using the software interface.
With the EnerVista 745 Setup running on your PC, it is possible to
• Program and modify setpoints
• Load/save setpoint files from/to disk
• Read actual values and monitor status
• Perform waveform capture and log data
• Plot, print, and view trending graphs of selected actual values
• Download and playback waveforms
• Get help on any topic
4.2.2
Hardware
Communications from the EnerVista 745 Setup to the 745 can be accomplished three
ways: RS232, RS485, and Ethernet communications. The following figures below illustrate
typical connections for RS232, RS485, and Ethernet communications.
4–8
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: INTERFACESINTERFACES
FIGURE 4–2: Communications using the front RS232 port
FIGURE 4–3: Communications using rear RS485 port
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
4–9
INTERFACESCHAPTER 4: INTERFACES
808839A1.CDR
FIGURE 4–4: Communications using rear Ethernet port
4.2.3
Installing the EnerVista 745 Setup Software
The following minimum requirements must be met for the EnerVista 745 Setup software to
operate on your computer.
• Pentium class or higher processor (Pentium II 400 MHz or better recommended)
• Microsoft Windows 98, 98SE, NT 4.0 (SP4 or higher), 2000, XP
• Internet Explorer version 4.0 or higher (required libraries)
• 128 MB of RAM (256 MB recommended)
• Minimum of 200 MB hard disk space
A list of qualified modems for serial communications is shown below:
• US Robotics external 56K Faxmodem 5686
• US Robotics external Sportster 56K X2
• PCTEL 2304WT V.92 MDC internal modem
After ensuring these minimum requirements, use the following procedure to install the
EnerVista 745 Setup software from the enclosed GE EnerVista CD.
Z Insert the GE EnerVista CD into your CD-ROM drive.
Z Click the Install Now button and follow the installation instructions to
install the no-charge EnerVista software on the local PC.
Z When installation is complete, start the EnerVista Launchpad
application.
4–10
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: INTERFACESINTERFACES
Z Click the IED Setup section of the Launch Pad window.
Z In the EnerVista Launch Pad window, click the Add Product button.
Z Select the 745 Transformer Protection System from the Install
Software window as shown below.
Z Select the Web option to ensure the most recent software release, or
select CD if you do not have a web connection, then
Z Click the Add Now button to list software items for the 745.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
4–11
INTERFACESCHAPTER 4: INTERFACES
EnerVista Launchpad will obtain the latest installation software from the Web or CD and
automatically start the installation process. A status window with a progress bar will be
shown during the downloading process.
Z Select the complete path, including the new directory name, where the
EnerVista 745 Setup software will be installed.
Z Click on Next to begin the installation.
The files will be installed in the directory indicated and the installation
program will automatically create icons and add EnerVista 745 Setup
software to the Windows start menu.
Z Click Finish to end the installation.
The 745 device will be added to the list of installed IEDs in the
EnerVista Launchpad window, as shown below.
4–12
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: INTERFACESINTERFACES
4.3
Connecting EnerVista 745 Setup to the relay
4.3.1
Configuring serial communications
Before starting, verify that the serial cable is properly connected to either the RS232 port
on the front panel of the device (for RS232 communications) or to the RS485 terminals on
the back of the device (for RS485 communications).
This example demonstrates an RS232 connection. For RS485 communications, the GE
Multilin F485 converter will be required. Refer to the F485 manual for additional details. To
configure the relay for Ethernet communications, see Configuring Ethernet
communications on page 4–15.
Z Install and start the latest version of the EnerVista 745 Setup software
(available from the GE EnerVista CD).
See the previous section for the installation procedure.
Z Click on the Device Setup button to open the Device Setup window.
Z Click the Add Site button to define a new site.
Z Enter the desired site name in the Site Name field.
If desired, a short description of the site can also be entered along with
the display order of devices defined for the site. In this example, we will
use “Transformer Station 1” as the site name.
Z Click the OK button when complete.
The new site will appear in the upper-left list in the EnerVista 745 Setup window.
Z Click the Add Device button to define the new device.
Z Enter the desired name in the Device Name field and a site description
(optional).
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
4–13
INTERFACESCHAPTER 4: INTERFACES
Z Select Serial from the Interface drop-down list.
This will display a number of interface parameters that must be entered
for proper RS232 functionality.
–
Enter the slave address and COM port values (from the S1 745 SETUP ZV SERIAL
PORTS menu) in the Slave Address and COM Port fields.
–
Enter the physical communications parameters (baud rate and parity setpoints)
in their respective fields.
Note that when communicating to the relay from the front port, the default
communications settings are a baud rate of 9600, with slave address of 1, no
parity, 8 bits, and 1 stop bit. These values cannot be changed.
Z Click the Read Order Code button to connect to the 745 device and
upload the order code.
If a communications error occurs, ensure that the 745 serial
communications values entered in the previous step correspond to the
relay setting values.
Z Click OK when the relay order code has been received.
The new device will be added to the Site List window (or Online
window) located in the top left corner of the main EnerVista 745 Setup
window.
The 745 site device has now been configured for serial communications. Proceed to
Connecting to the Relay on page 4–17 to begin communications.
4–14
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: INTERFACESINTERFACES
4.3.2
Using the Quick Connect Feature
The Quick Connect button can be used to establish a fast connection through the front
panel RS232 port of a 745 relay. The following window will appear when the Quick
Connect button is pressed:
As indicated by the window, the quick connect feature quickly connects the EnerVista 745
Setup software to a 745 front port with the following settings: 9600 baud, no parity, 8 bits,
1 stop bit. Select the PC communications port connected to the relay and press the
Connect button.
The EnerVista 745 Setup software will display a window indicating the status of
communications with the relay. When connected, a new Site called “Quick Connect” will
appear in the Site List window. The properties of this new site cannot be changed.
The 745 site device has now been configured via the Quick Connect feature for serial
communications. Proceed to Connecting to the Relay on page 4–17 to begin
communications.
4.3.3
Configuring Ethernet communications
Before starting, verify that the Ethernet cable is properly connected to the RJ45 Ethernet
port.
Z Install and start the latest version of the EnerVista 745 Setup software
(available from the GE EnerVista CD).
See the previous section for the installation procedure.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
4–15
INTERFACESCHAPTER 4: INTERFACES
Z Click on the Device Setup button to open the device setup window.
Z Click the Add Site button to define a new site.
Z Enter the desired site name in the Site Name field.
If desired, a short description of the site can also be entered along with
the display order of devices defined for the site. In this example, we will
use “Transformer Station 1” as the site name.
Z Click the OK button when complete.
The new site will appear in the upper-left list in the EnerVista 745 Setup window.
Z Click the Add Device button to define the new device.
Z Enter the desired name in the Device Name field and a description
(optional) of the site.
Z Select Ethernet from the Interface drop-down list.
This will display a number of interface parameters that must be entered
for proper Ethernet functionality.
Z Enter the IP address assigned to the 745 relay.
Z Enter the slave address and Modbus port values (from the S1 745
SETUP ZV COMMUNICATIONS menu) in the Slave Address and
Modbus Port fields.
Z Click the Read Order Code button to connect to the 745 device and
upload the order code.
If a communications error occurs, ensure that the 745 Ethernet
communications values entered in the previous step correspond to the
relay values.
Z Click OK when the relay order code has been received.
The new device will be added to the site list window (or online window)
located in the top left corner of the main EnerVista 745 Setup window.
4–16
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: INTERFACESINTERFACES
The 745 Site Device has now been configured for Ethernet communications. Proceed to
the following section to begin communications.
4.3.4
Connecting to the Relay
Now that the communications parameters have been properly configured, the user can
easily connect to the relay.
Z Expand the Site list by double clicking on the site name or clicking on
the «+» box to list the available devices for the given site (for example,
in the “Transformer Station 1” site shown below).
Desired device trees can be expanded by clicking the «+» box. The following list of headers
is shown for each device:
•
Device definitions
•
Settings
•
Actual values
•
Commands
•
Communications
Z Expand the Settings > Relay Setup list item.
Z Double click on Front Panel to open the Front Panel settings window as
shown below:
FIGURE 4–5: Main window after connection
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
4–17
INTERFACESCHAPTER 4: INTERFACES
The Front Panel settings window will open with a corresponding status indicator on the
lower left of the EnerVista 745 Setup window.
If the status indicator is red, verify that the serial cable is properly connected to the relay,
and that the relay has been properly configured for communications (steps described
earlier).
The front panel setpoints can now be edited, printed, or changed according to user
specifications. Other setpoint and commands windows can be displayed and edited in a
similar manner. Actual values windows are also available for display. These windows can
be locked, arranged, and resized at will.
Note
4–18
Refer to the EnerVista 745 Setup help file for additional information about the using the
software.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: INTERFACESINTERFACES
4.4
Working with Setpoints and Setpoint Files
4.4.1
Engaging a Device
The EnerVista 745 Setup software may be used in on-line mode (relay connected) to
directly communicate with a 745 relay. Communicating relays are organized and grouped
by communication interfaces and into sites. Sites may contain any number of relays
selected from the SR or UR product series.
4.4.2
Entering Setpoints
The system setup page will be used as an example to illustrate the entering of setpoints. In
this example, we will be changing the current sensing setpoints.
Z Establish communications with the relay.
Z Select the Setpoint > System Setup > Transformer menu item.
This can be selected from the device setpoint tree or the main window
menu bar.
Z Select the LOAD LOSS AT RATED LOAD setpoint by clicking anywhere in
the parameter box.
This will display three arrows: two to increment/decrement the value
and another to launch the numerical calculator.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
4–19
INTERFACESCHAPTER 4: INTERFACES
Z Click the arrow at the end of the box to display a numerical keypad
interface that allows the user to enter a value within the setpoint range
displayed near the top of the keypad:
Z Click Accept to exit from the keypad and keep the new value.
Z Click on Cancel to exit from the keypad and retain the old value.
For setpoints requiring non-numerical pre-set values (e.g. PHASE SEQUENCE),
Z Click anywhere within the setpoint value box to display a drop-down
selection menu arrow.
Z Click on the arrow to select the desired setpoint.
For setpoints requiring an alphanumeric text string (e.g. message scratchpad messages),
Z Enter the value directly within the setpoint value box.
Z In any settings window, click on Save to save the values into the 745.
Z Click Yes to accept any changes.
Z Click No, and then Restore to retain previous values and exit.
4–20
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: INTERFACESINTERFACES
4.4.3
File Support
Opening any EnerVista 745 Setup file will automatically launch the application or provide
focus to the already opened application. If the file is a settings file (has a ‘745’ extension)
which had been removed from the Settings List tree menu, it will be added back to the
Settings List tree.
New files will be automatically added to the tree, which is sorted alphabetically with
respect to settings file names.
4.4.4
Using Setpoints Files
4.4.4.1 Overview
The EnerVista 745 Setup software interface supports three ways of handling changes to
relay settings:
• In off-line mode (relay disconnected) to create or edit relay settings files for later
download to communicating relays.
• Directly modifying relay settings while connected to a communicating relay, then
saving the settings when complete.
• Creating/editing settings files while connected to a communicating relay, then
saving them to the relay when complete.
Settings files are organized on the basis of file names assigned by the user. A settings file
contains data pertaining to the following types of relay settings:
• Device definition
• Product setup
• System setup
• Logic inputs
• Protection elements
• Outputs
• Relay testing
• User memory map setting tool
Factory default values are supplied and can be restored after any changes.
The EnerVista 745 Setup display relay setpoints with the same hierarchy as the front panel
display. For specific details on setpoints, refer to Chapter 5.
4.4.4.2 Downloading and Saving Setpoints Files
Setpoints must be saved to a file on the local PC before performing any firmware
upgrades. Saving setpoints is also highly recommended before making any setpoint
changes or creating new setpoint files.
The EnerVista 745 Setup window, setpoint files are accessed in the Settings List control bar
window or the Files window. Use the following procedure to download and save setpoint
files to a local PC.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
4–21
INTERFACESCHAPTER 4: INTERFACES
Z Ensure that the site and corresponding device(s) have been properly
defined and configured as shown in EnerVista Software Interface on
page 4–8.
Z Select the desired device from the site list.
Z Select the File > Read Settings from Device menu item to obtain
settings information from the device.
After a few seconds of data retrieval, the software will request the name and destination
path of the setpoint file. The corresponding file extension will be automatically assigned.
Z Press Save to complete the process.
A new entry will be added to the tree, in the File pane, showing path and
file name for the setpoint file.
4.4.4.3 Adding Setpoints Files to the Environment
The EnerVista 745 Setup software provides the capability to review and manage a large
group of setpoint files. Use the following procedure to add a new or existing file to the list.
Z In the files pane, right-click on Files.
Z Select the Add Existing Setting File item as shown:
The Open dialog box will appear, prompting for a previously saved setpoint file. As for any
other Windows® application,
Z Browse for the file to add.
Z Click Open.
The new file and complete path will be added to the file list.
4.4.4.4 Creating a New Setpoint File
The EnerVista 745 Setup software allows the user to create new setpoint files independent
of a connected device. These can be uploaded to a relay at a later date. The following
procedure illustrates how to create new setpoint files.
4–22
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: INTERFACESINTERFACES
1.
In the File pane, right click on ‘File’ and select the New Settings File item. The
EnerVista 745 Setup software displays the following box will appear, allowing for the
configuration of the setpoint file for the correct firmware version. It is important to
define the correct firmware version to ensure that setpoints not available in a
particular version are not downloaded into the relay.
Z Select the software Revision for the new setpoint file.
Z Configure the Installed Options as shown.
Z For future reference, enter some useful information in the Description
box to facilitate the identification of the device and the purpose of the
file.
Z To select a file name and path for the new file, click the button beside
the File Name box.
Z Select the file name and path to store the file, or select any displayed file
name to update an existing file.
All 745 setpoint files should have the extension ‘745’ (for example,
‘motor1.745’).
Z Click Save and OK to complete the process.
Once this step is completed, the new file, with a complete path, will be
added to the EnerVista 745 Setup software environment.
4.4.4.5 Upgrading Setpoint Files to a New Revision
It is often necessary to upgrade the revision code for a previously saved setpoint file after
the 745 firmware has been upgraded (for example, this is required for firmware upgrades).
This is illustrated in the following procedure.
Z Establish communications with the 745 relay.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
4–23
INTERFACESCHAPTER 4: INTERFACES
Z Select the Actual > Product Info menu item and record the Software
Revision identifier of the relay firmware as shown below.
Z Load the setpoint file to be upgraded into the EnerVista 745 Setup
environment as described in Adding Setpoints Files to the Environment
on page 4–22.
Z In the File pane, select the saved setpoint file.
Z From the main window menu bar, select the File > Properties menu
item and note the version code of the setpoint file.
If this version (e.g. 4.0X shown below) is different than the Software
Revision code noted in step 2, select a New File Version that matches
the software revision code from the pull-down menu.
For example, if the software revision is 2.80 and the current setpoint file
revision is 4.00, change the setpoint file revision to “4.0X”, as shown
below.
Z When complete, click Convert to convert the setpoint file to the desired
revision.
A dialog box will request confirmation. See Loading Setpoints from a
File on page 4–26 for instructions on loading this setpoint file into the
745.
4–24
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: INTERFACESINTERFACES
4.4.4.6 Printing Setpoints and Actual Values
The EnerVista 745 Setup software allows the user to print partial or complete lists of
setpoints and actual values. Use the following procedure to print a list of setpoints:
Z Select a previously saved setpoints file in the File pane or establish
communications with a 745 device.
Z From the main window, select the File > Print Settings menu item.
The Print/Export Options dialog box will appear.
Z Select Settings in the upper section and select either Include All
Features (for a complete list) or Include Only Enabled Features (for a
list of only those features which are currently used) in the filtering
section.
Z Click OK.
The process for File > Print Preview Settings is identical to the steps above.
Setpoints lists can be printed in the same manner by right clicking on the desired file (in the
file list) or device (in the device list) and selecting the Print Device Information or Print
Settings File options.
A complete list of actual values can also be printed from a connected device with the
following procedure:
Z Establish communications with the desired 745 device.
Z From the main window, select the File > Print Settings menu item.
The Print/Export Options dialog box will appear.
Z Select Actual Values in the upper section and select either Include All
Features (for a complete list) or Include Only Enabled Features (for a
list of only those features which are currently used) in the filtering
section.
Z Click OK.
Actual values lists can be printed in the same manner by right clicking on the desired
device (in the device list) and selecting the Print Device Information option.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
4–25
INTERFACESCHAPTER 4: INTERFACES
4.4.4.7 Loading Setpoints from a File
An error message will occur when attempting to download a setpoint file with a
revision number that does not match the relay firmware. If the firmware has been
upgraded since saving the setpoint file, see Upgrading Setpoint Files to a New Revision
on page 4–23 for instructions on changing the revision number of a setpoint file.
The following procedure illustrates how to load setpoints from a file. Before loading a
setpoints file, it must first be added to the EnerVista 745 Setup environment as described
in Adding Setpoints Files to the Environment on page 4–22.
Z Select the previously saved setpoints file from the File pane of the
EnerVista 745 Setup software main window.
Z Select the File > Properties menu item and verify that the
corresponding file is fully compatible with the hardware and firmware
version of the target relay.
If the versions are not identical, see Upgrading Setpoint Files to a New
Revision on page 4–23 for details on changing the setpoints file version.
Z Right-click on the selected file and select the Write Settings to Device
item.
If the relay is currently in-service, the EnerVista 745 Setup software will
generate a warning message reminding the user to remove the relay
from service before attempting to load setpoints.
Z Select the target relay from the list of devices shown.
Z Click Send.
If there is an incompatibility, an error will occur informing the user of
incompatibilities:
If there are no incompatibilities between the target device and the Setpoints file, the data
will be transferred to the relay. An indication of the percentage completed will be shown in
the bottom of the main menu.
4–26
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: INTERFACESINTERFACES
4.5
Upgrading Relay Firmware
4.5.1
Description
To upgrade the 745 firmware, follow the procedures listed in this section. Upon successful
completion of this procedure, the 745 will have new firmware installed with the original
setpoints.
The latest firmware files are available from the GE Multilin website at http://
www.GEmultilin.com.
4.5.2
Saving Setpoints to a File
Before upgrading firmware, it is very important to save the current 745 settings to a file on
your PC. After the firmware has been upgraded, it will be necessary to load this file back
into the 745.
Refer to Downloading and Saving Setpoints Files on page 4–21 for details on saving relay
setpoints to a file.
4.5.3
Loading New Firmware
Loading new firmware into the 745 flash memory is accomplished as follows:
Z Connect the relay to the local PC and save the setpoints to a file as
shown in Downloading and Saving Setpoints Files on page 4–21.
Z Select the Communications > Update Firmware menu item.
The following warning message will appear.
Z Select Yes to proceed or No the cancel the process.
Do not proceed unless you have saved the current setpoints
An additional message will be displayed to ensure the PC is connected to the relay front
port, as the 745 cannot be upgraded via the rear RS485 ports.
The EnerVista 745 Setup software will request the new firmware file.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
4–27
INTERFACESCHAPTER 4: INTERFACES
Z Locate the firmware file to load into the 745.
The firmware filename has the following format:
Figure 4-1: Firmware file format
The EnerVista 745 Setup software automatically lists all filenames beginning with ‘33’.
Z Select the appropriate file and click OK to continue.
The software will prompt with another Upload Firmware Warning window. This will be the
final chance to cancel the firmware upgrade before the flash memory is erased.
Z Click Yes to continue or No to cancel the upgrade.
The EnerVista 745 Setup software now prepares the 745 to receive the new firmware file.
The 745 will display a message indicating that it is in Upload Mode. While the file is being
loaded into the 745, a status box appears showing how much of the new firmware file has
been transferred and how much is remaining, as well as the upgrade status. The entire
transfer process takes approximately five minutes.
The EnerVista 745 Setup software will notify the user when the 745 has finished loading
the file.
Z Carefully read any displayed messages and click OK to return the main
screen.
Note
Cycling power to the relay is recommended after a firmware upgrade.
After successfully updating the 745 firmware, the relay will not be in service and will
require setpoint programming. To communicate with the relay, the following settings will
have to be manually programmed.
SLAVE ADDRESS
COM1/COM2/FRONT BAUD RATE
COM1/COM2/FRONT PARITY (if applicable)
When communications is established, the saved setpoints must be reloaded back into the
relay. See Loading Setpoints from a File on page 4–26 for details.
4–28
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: INTERFACESINTERFACES
Modbus addresses assigned to firmware modules, features, settings, and corresponding
data items (i.e. default values, minimum/maximum values, data type, and item size) may
change slightly from version to version of firmware.
The addresses are rearranged when new features are added or existing features are
enhanced or modified. The EEPROM DATA ERROR message displayed after upgrading/
downgrading the firmware is a resettable, self-test message intended to inform users that
the Modbus addresses have changed with the upgraded firmware. This message does not
signal any problems when appearing after firmware upgrades.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
4–29
INTERFACESCHAPTER 4: INTERFACES
4.6
Advanced EnerVista 745 Setup Features
4.6.1
Triggered Events
While the interface is in either on-line or off-line mode, data generated by triggered
specified parameters can be viewed and analyzed via one of the following:
• Event recorder: The event recorder captures contextual data associated with the
last 256 events, listed in chronological order from most recent to the oldest.
• Oscillography: The oscillography waveform traces and digital states provide a
visual display of power system and relay operation data captured during specific
triggered events.
4.6.2
Waveform Capture (trace memory)
The EnerVista 745 Setup software can be used to capture waveforms (or view trace
memory) from the 745 relay at the instance of a trip. A maximum of 128 cycles can be
captured and the trigger point can be adjusted to anywhere within the set cycles. A
maximum of 32 waveforms can be buffered (stored) with the buffer/cycle trade-off.
The following waveforms can be captured:
• Phase A, B, and C currents (Ia, Ib, and Ic)
• Differential A, B, and C currents (Idiffa, Idiffb, and Idiffc)
• Ground currents (Ig)
• Phase A-N, B-N, and C-N voltages (Va, Vb, and Vc)
• Digital data for output relays and contact input states
Z With EnerVista 745 Setup running and communications established,
select the Actual > Waveform Capture menu item to open the
waveform capture setup window:
Z Click on Trigger Waveform to trigger a waveform capture.
4–30
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: INTERFACESINTERFACES
The waveform file numbering starts with the number zero in the 745; therefore, the
maximum trigger number will always be one less then the total number triggers available.
Z Click on the Save to File button to save the selected waveform to the
local PC.
A new window will appear requesting for file name and path.
The file is saved as a COMTRADE file, with the extension ‘CFG’. In addition to the COMTRADE
file, two other files are saved. One is a CSV (comma delimited values) file, which can be
viewed and manipulated with compatible third-party software. The other file is a DAT File,
required by the COMTRADE file for proper display of waveforms.
Z To view a previously saved COMTRADE file, click the Open button
and select the corresponding COMTRADE file.
Z To view the captured waveforms, click the Launch Viewer button. A
detailed waveform capture window will appear as shown below:
FIGURE 4–6: Waveform capture window attributes
The red vertical line indicates the trigger point of the relay.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
4–31
INTERFACESCHAPTER 4: INTERFACES
The date and time of the trip is displayed at the top left corner of the window. To match the
captured waveform with the event that triggered it, make note of the time and date shown
in the graph. Then, find the event that matches the same time and date in the event
recorder. The event record will provide additional information on the cause and the system
conditions at the time of the event. Additional information on how to download and save
events is shown in Event Recorder on page 4–35.
Z From the window main menu bar, press the Preference button to open
the Comtrade Setup page to change the graph attributes.
The following window will appear:
Z Change the Color of each graph as desired, and select other options as
required, by checking the appropriate boxes.
Z Click OK to store these graph attributes, and to close the window.
The Waveform Capture window will reappear with the selected graph attributes available
for use.
4.6.3
Trending (data logger)
The trending or data logger feature is used to sample and record up to eight actual values
at an interval defined by the user. Several parameters can be trended and graphed at
sampling periods ranging from 1 second up to 1 hour. The parameters which can be
trended by the EnerVista 745 Setup software are:
4–32
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: INTERFACESINTERFACES
•
Currents/voltages:
–
•
•
•
–
Positive-, negative-, and zero-sequence currents for windings 1, 2, and 3
–
Ia, Ib, and Ic differential and restraint currents
–
System frequency
–
Frequency decay rate
Harmonics:
–
Total harmonic distortion (THD)
–
Harmonic derating factor
Temperature:
–
Ambient temperature
–
Hottest-spot winding temperature
–
RTDs 1 through 12
Demand:
–
•
Ia, Ib, Ic, In, and Ig currents for windings 1, 2, and 3
Current demand for Windings 1, 2, and 3
Others:
–
Analog inputs 1, 2, 3, and 4
–
Accumulated loss-of-life
–
Aging factor
–
Tap changer position
Z With EnerVista 745 Setup running and communications established,
select the Actual Values > Trending menu item to open the trending
window.
Z To prepare for new trending, select Stop to stop the data logger and
Reset to clear the screen.
Z Select the graphs to be displayed through the pull-down menu beside
each channel description.
Z Select the sample rate through the pull-down menu.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
4–33
INTERFACESCHAPTER 4: INTERFACES
If you want to save the information captured by trending,
Z Check the box besides Log Samples to File.
The following dialog box will appear requesting for file name and path. The file is saved as
'csv' (comma separated values) file, which can be viewed and manipulated with
compatible third-party software. Ensure that the sample rate not less than 5 seconds,
otherwise some data may not get written to the file.
Z To limit the size of the saved file, enter a number in the Limit File
Capacity To box.
The minimum number of samples is 1000. At a sampling rate of 5
seconds (or 1 sample every 5 seconds), the file will contain data
collected during the past 5000 seconds. The EnerVista 745 Setup
software will automatically estimate the size of the trending file.
Z Press “Run” to start the data logger.
If the Log Samples to File item is selected, the EnerVista 745 Setup
software will begin collecting data at the selected sampling rate and will
display it on the screen.
The data log will continue until the Stop button is pressed or until the
selected number of samples is reached, whichever occurs first.
4–34
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: INTERFACESINTERFACES
During the process of data logging, the trending screen appears as shown below.
Figure 4-2: Trending screen
4.6.4
Event Recorder
The 745 event recorder can be viewed through the EnerVista 745 Setup software. The
event recorder stores transformer and system information each time an event occurs. A
maximum of 256 events can be stored, where E256 is the most recent event and E001 is
the oldest event. E001 is overwritten whenever a new event occurs. Refer to Event Records
on page 6–17 for additional information on the event recorder.
Use the following procedure to view the event recorder with EnerVista 745 Setup:
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
4–35
INTERFACESCHAPTER 4: INTERFACES
Z With EnerVista 745 Setup running and communications established,
select the Actual > Event Recorder item from the main menu.
This displays the Event Recorder window indicating the list of recorded
events, with the most current event displayed first.
Figure 4-3: Event recorder window
To view detailed information for a given event and the system information at the moment
of the event occurrence,
Z Change the event number on the Select Events box.
4.6.5
Modbus User Map
The EnerVista 745 Setup software provides a means to program the 745 user map
(Modbus addresses 0180h to 01F7h). Refer to GE publication GEK-106636B: 745
Communications Guide for additional information on the user map.
Z Select a connected device in EnerVista 745 Setup.
Z Select the Setpoint > User Map menu item to open the following
window.
4–36
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: INTERFACESINTERFACES
This window allows the desired addresses to be written to User Map locations. The User
Map values that correspond to these addresses are then displayed.
4.6.6
Viewing Actual Values
You can view real-time relay data such as input/output status and measured parameters.
Z From the main window menu bar, select Actual Values to open a
window with tabs, each tab containing data in accordance to the
following list:
1.
System status:
• The status of the logic inputs and virtual inputs/outputs
• Targets.
• The status of the output relays.
• Any self-test errors.
2.
Metering data:
• Instantaneous current measurements including phase, neutral,
and ground currents for each winding, along with differential,
restraint, positive-sequence, negative-sequence, zero-sequence,
and ground restraint currents.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
4–37
INTERFACESCHAPTER 4: INTERFACES
• Harmonic metering up to the 21st harmonic, total harmonic
distortion (THD), as well as harmonic derating factor.
• Phase-to-neutral voltage metering, volts-per-hertz, and system
frequency.
• Tap changer position.
• Current demand for each winding including peak values.
• Real, reactive, and apparent power for each winding, along with
the power factor.
• Energy metering (Wh and varh) for each winding
• Transformer loss-of-life and ambient temperature metering
• Analog inputs.
3.
Event recorder downloading tool.
4.
Product information including model number, firmware version, additional
product information, and calibration dates.
5.
Oscillography and data logger downloading tool.
Z Select an actual values window to also open the actual values tree from
the corresponding device in the site list and highlight the current
location in the hierarchy.
For complete details on actual values, refer to Chapter 6.
To view a separate window for each group of actual values,
Z Select the desired item from the tree.
Z Double click with the left mouse button.
Each group will be opened on a separate tab. The windows can be rearranged to maximize data viewing as shown in the following figure
(showing actual demand, harmonic contents, and current values tiled in
the same window):
4–38
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: INTERFACESINTERFACES
Figure 4-4: Actual values display
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
4–39
INTERFACESCHAPTER 4: INTERFACES
4.7
Using EnerVista Viewpoint with the 745
4.7.1
Plug and Play Example
EnerVista Viewpoint is an optional software package that puts critical 745 information
onto any PC with plug-and-play simplicity. EnerVista Viewpoint connects instantly to the
745 via serial, ethernet or modem and automatically generates detailed overview,
metering, power, demand, energy and analysis screens. Installing EnerVista Launchpad
(see previous section) allows the user to install a fifteen-day trial version of EnerVista
Viewpoint. After the fifteen day trial period you will need to purchase a license to continue
using EnerVista Viewpoint. Information on license pricing can be found at http://
www.enervista.com.
Z Install the EnerVista Viewpoint software from the GE EnerVista CD.
Z Ensure that the 745 device has been properly configured for either serial
or Ethernet communications (see previous sections for details).
Z Click the Viewpoint window in EnerVista to log into EnerVista
Viewpoint. At this point, you will be required to provide a login and
password if you have not already done so.
Figure 4-5: EnerVista Viewpoint main window
Z Click the Device Setup button to open the Device Setup window.
Z Click the Add Site button to define a new site.
Z Enter the desired site name in the Site Name field.
If desired, a short description of site can also be entered along with the
display order of devices defined for the site.
Z Click the OK button when complete.
The new site will appear in the upper-left list in the EnerVista 745 Setup
window.
Z Click the Add Device button to define the new device.
Z Enter the desired name in the Device Name field and a description
(optional) of the site.
4–40
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: INTERFACESINTERFACES
Z Select the appropriate communications interface (Ethernet or Serial) and
fill in the required information for the 745. See EnerVista Software
Interface on page 4–8 for details.
Figure 4-6: Device setup screen (example)
Z Click the Read Order Code button to connect to the 745 device and
upload the order code.
If a communications error occurs, ensure that communications values
entered in the previous step correspond to the relay setting values.
Z Click OK when complete.
Z From the EnerVista main window, select the IED Dashboard item to
open the Plug and Play IED dashboard. An icon for the 745 will be
shown.
FIGURE 4–7: ‘Plug and play’ dashboard
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
4–41
INTERFACESCHAPTER 4: INTERFACES
6.
Click the Dashboard button below the 745 icon to view the device information.
We have now successfully accessed our 745 through EnerVista Viewpoint.
FIGURE 4–8: EnerVista plug and play screens (example)
For additional information on EnerVista viewpoint, please visit the EnerVista website at
http://www.enervista.com.
4–42
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
GE Consumer & Industrial
Multilin
745 Transformer Protection
System
Chapter 5: Setpoints
Setpoints
5.1
Overview
5.1.1
Setpoint Message Map
The 745 relay has a considerable number of programmable settings (setpoints) that makes
it extremely flexible. The setpoints have been grouped into a number of pages as shown
below. If using the EnerVista 745 Setup software and not connected to a relay, you may
have to select the File > Properties menu item and set the correct options for your relay.
„ SETPOINTS
[ Z]
„ PASSCODE
[Z]
S1 745 SETUP
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
[ Z]
„ PREFERENCES
„ COMMUNICATIONS [Z]
[Z]
„ RESETTING
„ CLOCK
[Z]
„ DEFAULT
[ Z]
[ Z]
„ INSTALLATION [Z]
„ UPGRADE
[Z]
OPTIONS
„ SETUP EVENT
RECORDER
See page 5–25
See page 5–26
See page 5–29
See page 5–29
MESSAGES
„ SCRATCHPAD
See page 5–25
[ Z]
See page 5–30
See page 5–31
See page 5–31
See page 5–31
See page 5–33
5–1
SETPOINTSCHAPTER 5: SETPOINTS
MESSAGE
[Z]
S2 SYSTEM SETUP
„ SETPOINTS
[Z]
„ TRANSFORMER
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
[Z]
S3 LOGIC INPUTS
„ WINDING 1
[ Z]
„ WINDING 2
[ Z]
„ WINDING 3
[ Z]
[Z]
„ ONLOAD TAP
CHANGER
„ HARMONICS
[Z]
„ FLEXCURVES
[Z]
„ VOLTAGE INPUT [Z]
„ AMBIENT TEMP [Z]
„ ANALOG INPUT [Z]
„ DEMAND
[Z]
METERING
„ ANALOG OUTPUTS [Z]
MESSAGE
MESSAGE
[Z]
„ VIRTUAL INPUTS [Z]
„ SETPOINT GROUP [Z]
MESSAGE
MESSAGE
5–2
See page 5–36
See page 5–36
See page 5–36
See page 5–37
See page 5–38
See page 5–38
See page 5–39
See page 5–39
See page 5–41
See page 5–41
See page 5–43
See page 5–44
See page 5–45
„ END OF PAGE S3
S4 ELEMENTS
MESSAGE
See page 5–34
„ END OF PAGE S2
„ LOGIC INPUTS [Z]
„ SETPOINTS
„ SETPOINTS
„ END OF PAGE S1
„ DIFFERENTIAL [Z]
[Z]
DIFFERENTIAL
„ INST
„ PHASE OC
[ Z]
See page 5–47
See page 5–48
See page 5–57
See page 5–58
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
„ SETPOINTS
„ NEUTRAL OC
[Z]
„ GROUND OC
[Z]
„ RESTRICTED
[Z]
GROUND
[ Z]
„ NEG SEQ OC
[ Z]
„ FREQUENCY
„ OVEREXCITATION [Z]
[ Z]
„ HARMONICS
[Z]
„ INSULATION
AGING
„ ANALOG INPUT [Z]
„ CURRENT DEMAND [Z]
[Z]
„ XFORMER
OVERLOAD
[Z]
„ TAP CHANGER
FAILURE
S5 OUTPUTS
MESSAGE
MESSAGE
MESSAGE
MESSAGE
„ SETPOINTS
„ TRACE MEMORY [Z]
[ Z]
„ VIRTUAL
OUTPUTS
„ TIMERS
[ Z]
S6 TESTING
MESSAGE
MESSAGE
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
See page 5–72
See page 5–76
See page 5–78
See page 5–83
See page 5–88
See page 5–90
See page 5–94
See page 5–95
See page 5–96
See page 5–97
See page 5–102
See page 5–105
See page 5–106
See page 5–106
„ END OF PAGE S5
„ OUTPUT RELAYS [Z]
[Z]
See page 5–69
„ END OF PAGE S4
„ OUTPUT RELAYS [Z]
[Z]
See page 5–66
„ ANALOG OUTPUTS [Z]
„ SIMULATION
[ Z]
See page 5–107
See page 5–108
See page 5–108
5–3
SETPOINTSCHAPTER 5: SETPOINTS
MESSAGE
MESSAGE
5.1.2
„ FACTORY
[ Z]
SERVICE
See page 5–112
„ END OF PAGE S6
Setpoint entry
Prior to commissioning the 745 relay, setpoints defining transformer characteristics,
inputs, output relays, and protection settings must be entered, via one of the following
methods:
• Front panel, using the keypad and display.
• Front panel RS232, rear terminal RS485/RS422, or Ethernet communication ports,
and a portable computer running the EnerVista 745 Setup software or a SCADA
system running user-written software.
Any of these methods can be used to enter the same information. A computer, however,
makes entry much easier. Files can be stored and downloaded for fast, error free entry
when a computer is used. Settings files can be prepared and stored on disk without the
need to connect to a relay.
All setpoint messages are illustrated and described in blocks throughout this chapter. The
745 relay leaves the factory with setpoints programmed to default values, and it is these
values that are shown in all the setpoint message illustrations. Some of these factory
default values can be left unchanged.
There are many 745 setpoints that must be entered for the relay to function correctly. In
order to safeguard against installation when these setpoints have not been entered, the
745 does not allow signaling of any output relay. In addition, the In Service LED is off and
the Self-Test Error LED on until the S1 745 SETUP ZV INSTALLATION Z 745 SETPOINTS value
is set to “Programmed”. This setpoint is defaulted to “Not Programmed” when the relay
leaves the factory. The SETPOINTS HAVE NOT BEEN PROGRAMMED diagnostic message
appears until the 745 is put in the programmed state:
Messages may vary somewhat from those illustrated because of installed options. Also,
some messages associated with disabled features (or optional features which have not
been ordered) are hidden. These messages are shown with a shaded message box.
• Keypad entry: See Using the Relay on page 1–3 for details on maneuvering
through the messages, viewing actual values, and changing setpoints.
• Computer entry: Setpoint values are grouped together on a screen in the
EnerVista 745 Setup software. The data is organized in a system of menus. See
EnerVista Software Interface on page 4–8 for details.
• SCADA entry: Details of the complete communication protocol for reading and
writing setpoints are given in chapters 8 and 9. A programmable SCADA system
connected to the RS485/RS422 terminals can make use of communication
commands for remote setpoint programming, monitoring, and control.
5.1.3
Setpoint Write Access
The 745 design incorporates hardware and passcode security features to provide
protection against unauthorized setpoint changes.
5–4
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
A hardware jumper must be installed across the setpoint access terminals on the back of
the relay to program new setpoints using the front panel keys. When setpoint
programming is via a computer connected to the communication ports, no setpoint
access jumper is required.
Passcode protection may also be enabled. When enabled, the 745 requests a numeric
passcode before any setpoint can be entered. As an additional safety measure, a minor
self-test error is generated when the passcode is entered incorrectly three times in a row.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–5
SETPOINTSCHAPTER 5: SETPOINTS
5.2
Auto-configuration
5.2.1
Introduction
For transformer differential protection, it is necessary to correct the magnitude and phase
relationships of the CT secondary currents for each winding, in order to obtain near zero
differential currents under normal operating conditions. Traditionally, this has been
accomplished using interposing CTs or tapped relay windings and compensating CT
connections at the transformer.
The 745 simplifies CT configuration issues by having all CTs connected Wye (polarity
markings pointing away from the transformer). All phase angle and magnitude corrections,
as well as zero-sequence current compensation, are performed automatically based upon
user entered setpoints.
This section describes the process of auto-configuration by means of a specific example,
showing how CT ratios, transformer voltage ratios, and the transformer phase shifts are
used to generate correction factors. These correction factors are applied to the current
signals to obtain extremely accurate differential currents.
Consider a typical wye-delta power transformer with the following data:
• Connection: Y/d30° (i.e. delta winding phases lag corresponding wye winding
phases by 30°)
• Winding 1: 100/133/166 MVA, 220 kV nominal, 500/1 CT ratio
• Winding 2: 100/133/166 MVA, 69 kV nominal, 1500/1 CT ratio
onload tap changer: 61 to 77 kV in 0.5 kV steps (33 tap positions)
• Auxiliary cooling: two stages of forced air
The following sections will illustrate auto-configuration principles using this example.
5.2.2
Dynamic CT Ratio Mismatch Correction
5.2.2.1 Use of Standard CT Ratios
• Standard CT ratios: CT2 / CT1=V1 / V2
• Tapped relay windings / interposing CTs (inaccurate/expensive)
Solution:
• Wx Nom Voltage, Wx rated Load, Wx CT primary setpoints
• Automatic correction for mismatch: (CT2 × V2) / (CT1 × V1) < 16
Even ignoring the onload tap changer, the 1500/1 CT on winding 2 does not perfectly
match the 500/1 CT on winding 1. A perfectly matched winding 2 CT ratio (at nominal
winding 2 voltage) is calculated as follows:
V1
500 220 kV
1594.2
CT 2 (ideal) = CT 1 × ----- = --------- × ----------------- = ----------------V2
1
69 kV
1
5–6
(EQ 5.1)
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
where
CT1 = winding 1 CT ratio
V1 = winding 1 nominal voltage
CT2 = winding 2 CT ratio
V2 = winding 2 nominal voltage
Thus, for any load, the winding 2 CT secondary current is higher (per unit) than the
winding 1 CT secondary current. The mismatch factor is 1594.2 / 1500 = 1.063.
The transformer type is entered as S2 SYSTEM SETUP Z TRANSFORMER ZV TRANSFORMER
TYPE. The 745 calculates and automatically corrects for CT mismatch to a maximum
mismatch factor of 16. The following information is entered as setpoints:
S2 SYSTEM SETUP ZV WINDING 1 Z WINDING 1 NOM F-F VOLTAGE: “220 kV”
S2 SYSTEM SETUP ZV WINDING 1 ZV WINDING 1 RATED LOAD: “100 MVA”
S2 SYSTEM SETUP ZV WINDING 1 ZV WINDING 1 PHASE CT PRIMARY: “500:1 A”
S2 SYSTEM SETUP ZV WINDING 2 Z WINDING 2 NOM F-F VOLTAGE: “69.0 kV”
S2 SYSTEM SETUP ZV WINDING 2 ZV WINDING 2 RATED LOAD: “100 MVA”
S2 SYSTEM SETUP ZV WINDING 2 ZV WINDING 2 PHASE CT PRIMARY: “1500:1 A”
For a three-winding transformer, the setpoints under the S2 SYSTEM SETUP ZV WINDING 3
menu must also be set.
5.2.2.2 Onload Tap Changer
• Onload tap changer
• Variable voltage ratio
• CT2 / CT1 = V1 / V2
• Lower sensitivity on differential element
Solution:
• Tap position monitoring: V2 = Vmin + (n – 1)Vincr
For example, the onload tap changer changes the winding 2 voltage, resulting in an even
greater CT mismatch. A perfectly matched winding 2 CT ratio (based on the tap changer
position) is calculated as follows:
V1
500
220
CT 2 (ideal) = CT 1 × --------------------------------------------------------- = --------- × ------------------------------------V 2 ( min ) + V 2 ( tap ) ( n – 1 )
1
61 + 0.5 ( n – 1 )
where
(EQ 5.2)
n = current tap changer position
V2(min) = winding 2 minimum voltage (at n = 1)
V2(tap) = winding 2 voltage increment per tap
Thus, with the tap changer at position 33, the Winding 2 CT ratio must be 1428.6 / 1 to be
perfectly matched. In this case, the mismatch factor is 1428.6 / 1500 = 0.952.
The 745 allows monitoring of the tap changer position via the tap position input. With this
input, the 745 dynamically adjusts the CT ratio mismatch factor based on the actual
transformer voltage ratio set by the tap changer.
Tap changers are operated by means of a motor drive unit mounted on the outside of the
transformer tank. The motor drive is placed in a protective housing containing all devices
necessary for operation, including a tap position indication circuit. This indication circuit
has a terminal for each tap with a fixed resistive increment per tap. A cam from the drive
shaft that provides local tap position indication also controls a wiper terminal in the
indication circuit, as illustrated below.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–7
SETPOINTSCHAPTER 5: SETPOINTS
R
R
R
R
TAP 4
TAP 3
R
TAP 2
TAP 6
R
WIPER
AT TAP 5
TAP 1
TAP 7
R
R
ZERO
POSITION
TAP 8
R
TAP 9
etc.
WIPER
TERMINAL
(to TAP POSITION +)
ZERO POSITION
TERMINAL
(to TAP POSITION -)
FIGURE 5–1: Tap position input
The “zero position” terminal and the “wiper” terminal of the tap position circuit are
connected to the positive and negative 745 tap position terminals. Polarity is not
consequential. The following setpoints configure the 745 to determine tap position. In the
S2 SYSTEM SETUP ZV ONLOAD TAP CHANGER setpoint menu, make the following settings:
WINIDNG WITH TAP CHANGER: “Winding 2”
NUMBER OF TAP POSITIONS: “33”
MINIMUM TAP POSITION VOLTAGE: “61.0 kV”
VOLTAGE INCREMENT PER TAP: “0.50 kV”
RESISTANCE INCREMENT PER TAP: “33 Ω”
The maximum value resistance on the top tap is 5 kΩ.
5.2.3
Phase Shifts on Three-phase Transformers
Power transformers that are built in accordance with ANSI and IEC standards are required
to identify winding terminals and phase relationships among the windings of the
transformer.
ANSI standard C.37.12.70 requires that the labels of the terminals include the characters 1,
2, and 3 to represent the names of the individual phases. The phase relationship among
the windings must be shown as a phasor diagram on the nameplate, with the winding
terminals clearly labeled. This standard specifically states that the phase relationships are
established for a condition where the source phase sequence of 1-2-3 is connected to
transformer windings labeled 1, 2 and 3 respectively.
IEC standard 60076-1 (1993) states that the terminal markings of the three phases follow
national practice. The phase relationship among the windings is shown as a specified
notation on the nameplate, and there may be a phasor diagram. In this standard the
arbitrary labeling of the windings is shown as I, II, and III. This standard specifically states
that the phase relationships are established for a condition where a source phase
sequence of I - II - III is connected to transformer windings labeled I, II and III respectively.
5–8
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
The source phase sequence must be stated when describing the winding phase
relationships since these relationships change when the phase sequence changes. The
example below shows why this happens, using a transformer described in IEC
nomenclature as “Yd1” or in GE Multilin nomenclature as “Y/d30.”
FIGURE 5–2: Example transformer
The above figure shows the physical connections within the transformer that produce a
phase angle in the delta winding that lags the respective wye winding by 30°. The winding
currents are also identified. Note that the total current out of the delta winding is described
by an equation. Now assume that a source, with a sequence of ABC, is connected to
transformer terminals ABC, respectively. The currents that would be present for a balanced
load are shown below.
FIGURE 5–3: Phasors for ABC sequence
Note that the delta winding currents lag the wye winding currents by 30°, which is in
agreement with the transformer nameplate.
Now assume that a source, with a sequence of ACB is connected to transformer terminals
A, C, B respectively. The currents that would be present for a balanced load are shown
below:
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–9
SETPOINTSCHAPTER 5: SETPOINTS
FIGURE 5–4: Phasors for ACB sequence
Note that the delta winding currents leads the wye winding currents by 30°, (which is a
type Yd11 in IEC nomenclature and a type Y/d330 in GE Multilin nomenclature) which is in
disagreement with the transformer nameplate. This is because the physical connections
and hence the equations used to calculate current for the delta winding have not changed.
The transformer nameplate phase relationship information is only correct for a stated
phase sequence.
It may be suggested that for the ACB sequence the phase relationship can be returned to
that shown on the transformer nameplate by connecting source phases A, B and C to
transformer terminals A, C, and B respectively. This will restore the nameplate phase shifts
but will cause incorrect identification of phases B and C within the relay, and is therefore
not recommended.
All information presented in this manual is based on connecting the relay phase A, B and C
terminals to the power system phases A, B and C respectively. The transformer types and
phase relationships presented are for a system phase sequence of ABC, in accordance
with the standards for power transformers. Users with a system phase sequence of ACB
must determine the transformer type for this sequence.
5.2.4
Phase Angle Correction
The following diagram shows the internal connections of the Y/d30° transformer of our
example:
A
a
WINDING 1 (WYE)
C
B
N
b
c
WINDING 2 (DELTA)
FIGURE 5–5: Wye/delta (30° lag) transformer
5–10
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
Under balanced conditions, the winding 2 phase current phasors lag the corresponding
phase current phasors of winding 1 by 30°. With CTs connected in a wye arrangement
(polarity markings pointing away from the transformer), the corresponding phase currents
cannot be summed directly to obtain a zero differential current, since corresponding
phasors will NOT be 180° out-of-phase.
Traditionally, this problem is solved by connecting the CTs on the wye side of the
transformer (winding 1) in a delta arrangement. This compensates for the phase angle lag
introduced in the delta side (winding 2).
The 745 performs this phase angle correction internally based on the following setpoint.
Set S2 SYSTEM SETUP Z TRANSFORMER ZV TRANSFORMER TYPE to “Y/d30°”.
The 745 supports over 100 two and three-winding transformer types. Table 5–1:
Transformer types on page 5–13 provides the following information about each
transformer type:
As shown in the “Y/d30°” entry of the transformer types table, the phase angle correction
(or phase shift) introduces 30° lag in winding 1. This lag is described in Phase shifts on page
5–24. This table provides the following information about each phase shift type:
5.2.5
Zero-sequence Component Removal
1.
If zero-sequence current can flow into and out of one transformer winding (e.g. a
grounded wye or zig-zag winding) but not the other winding (e.g. a delta winding),
external ground faults will cause the differential element to operate incorrectly.
Traditionally, this problem is solved by delta connecting the CTs on the wye side of a
wye/delta transformer so that the currents coming to the relay are both phase
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–11
SETPOINTSCHAPTER 5: SETPOINTS
corrected and void of zero-sequence current. Because the 745 software mimics the
CT delta connection, the zero-sequence current is automatically removed from all
Wye or zig-zag winding currents of transformers having at least one delta winding.
5–12
2.
External ground faults also cause maloperation of the differential element for
transformers having an in-zone grounding bank on the delta side (and the wye
connected CTs on the same side). Traditionally, this problem is solved by inserting a
zero-sequence current trap in the CT circuitry. The 745 automatically removes zerosequence current from all delta winding currents when calculating differential current.
Where there is no source of zero-sequence current (e.g. delta windings not having a
grounding bank), the 745 effectively removes nothing.
3.
Autotransformers have an internal tertiary winding to provide a path for thirdharmonic currents and control transient overvoltages. Also, many two-winding wye/
wye transformers have a three-legged core construction that forces zero-sequence
flux into the transformer tank, creating an inherent delta circuit. In both these cases,
there is zero-sequence impedance between the primary and secondary windings. The
745 removes zero-sequence current from all wye/wye and wye/wye/wye transformer
windings to prevent possible relay maloperations resulting from these two conditions.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
5.2.6
Transformer Types
A complete table of transformer types is shown below.
Table 5–1: Transformer types (Sheet 1 of 11)
Transformer
type
2W External
Correction
Y/y180°
Y/d150°
Y/d330°
D/d60°
D/d180°
D/d300°
Wdg.
Connection
Voltage
phasors
Phase
shift
1
WYE
(gnd 1/2)
0°
2
WYE
(gnd 2/3)
0°
0°
1
WYE
(gnd 1/2)
180°
lag
2
WYE
(gnd 2/3)
180° lag
0°
1
WYE
(gnd 1/2)
150°
lag
2
DELTA
(gnd 2/3)
150° lag
0°
1
WYE
(gnd 1/2)
330°
lag
2
DELTA
(gnd 2/3)
330° lag
0°
1
DELTA
(gnd 1/2)
60°
lag
2
DELTA
(gnd 2/3)
60° lag
0°
1
DELTA
(gnd 1/2)
180°
lag
2
DELTA
(gnd 2/3)
180° lag
0°
1
DELTA
(gnd 1/2)
300°
lag
2
DELTA
(gnd 2/3)
300° lag
0°
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
Transformer
type
Y/y0°
Y/d30°
Y/d210°
D/d0°
D/d120°
D/d240°
D/y30°
Wdg.
Connection
Voltage
phasors
Phase
shift
1
WYE
(gnd 1/2)
0°
2
WYE
(gnd 2/3)
0°
0°
1
WYE
(gnd 1/2)
30° lag
2
DELTA
(gnd 2/3)
30° lag
0°
1
WYE
(gnd 1/2)
210°
lag
2
DELTA
(gnd 2/3)
210° lag
0°
1
DELTA
(gnd 1/2)
0°
2
DELTA
(gnd 2/3)
0°
0°
1
DELTA
(gnd 1/2)
120°
lag
2
DELTA
(gnd 2/3)
120° lag
0°
1
DELTA
(gnd 1/2)
240°
lag
2
DELTA
(gnd 2/3)
240° lag
0°
1
DELTA
(gnd 1/2)
0°
2
WYE
(gnd 2/3)
30° lag
330°
lag
5–13
SETPOINTSCHAPTER 5: SETPOINTS
Table 5–1: Transformer types (Sheet 2 of 11)
Transformer
type
D/y150°
D/y330°
Y/z150°
Y/z330°
D/z60°
D/z180°
D/z300°
5–14
Wdg.
Connection
Voltage
phasors
Phase
shift
1
DELTA
(gnd 1/2)
0°
2
WYE
(gnd 2/3)
150° lag
210°
lag
1
DELTA
(gnd 1/2)
0°
2
WYE
(gnd 2/3)
330° lag
30° lag
1
WYE
(gnd 1/2)
150°
lag
2
ZIG-ZAG
(gnd 2/3)
150° lag
0°
1
WYE
(gnd 1/2)
330°
lag
2
ZIG-ZAG
(gnd 2/3)
330° lag
0°
1
DELTA
(gnd 1/2)
60° lag
2
ZIG-ZAG
(gnd 2/3)
60° lag
0°
1
DELTA
(gnd 1/2)
180° lag
2
ZIG-ZAG
(gnd 2/3)
180° lag
0°
1
DELTA
(gnd 1/2)
300°
lag
2
ZIG-ZAG
(gnd 2/3)
300° lag
0°
Transformer
type
D/y210°
Y/z30°
Y/z210°
D/z0°
D/z120°
D/z240°
3W External
Correction
Wdg.
Connection
Voltage
phasors
Phase
shift
1
DELTA
(gnd 1/2)
0°
2
WYE
(gnd 2/3)
210° lag
150°
lag
1
WYE
(gnd 1/2)
30° lag
2
ZIG-ZAG
(gnd 2/3)
30° lag
0°
1
WYE
(gnd 1/2)
210°
lag
2
ZIG-ZAG
(gnd 2/3)
210° lag
0°
1
DELTA
(gnd 1/2)
0°
2
ZIG-ZAG
(gnd 2/3)
0° lag
0°
1
DELTA
(gnd 1/2)
120°
lag
2
ZIG-ZAG
(gnd 2/3)
120° lag
0°
1
DELTA
(gnd 1/2)
240°
lag
2
ZIG-ZAG
(gnd 2/3)
240° lag
0°
1
WYE
0°
2
WYE
0°
0°
3
WYE
0°
0°
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
Table 5–1: Transformer types (Sheet 3 of 11)
Transformer
type
Y/y0°/d30°
Y/y0°/d210°
Y/y180°/d30°
Y/y180°/
d210°
Y/d30°/y0°
Wdg.
Connection
Voltage
phasors
Phase
shift
1
WYE
30°
lag
2
WYE
0°
3
Wdg.
Connection
1
WYE
150°
lag
30°
lag
2
WYE
0°
150°
lag
DELTA
30° lag
0°
3
DELTA
150° lag
0°
1
WYE
210°
lag
1
WYE
330°
lag
2
WYE
0°
210°
lag
2
WYE
0°
330°
lag
3
DELTA
210° lag
0°
3
DELTA
330° lag
0°
1
WYE
30°
lag
1
WYE
150°
lag
2
WYE
180° lag
210°
lag
2
WYE
180° lag
330°
lag
3
DELTA
30° lag
0°
3
DELTA
150° lag
0°
1
WYE
210°
lag
1
WYE
330°
lag
2
WYE
180° lag
30°
lag
2
WYE
180° lag
150°
lag
3
DELTA
210° lag
0°
3
DELTA
330° lag
0°
1
WYE
30° lag
1
WYE
30° lag
2
DELTA
30° lag
0°
2
DELTA
30° lag
0°
3
WYE
0°
30° lag
3
WYE
180° lag
210° lag
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
Transformer
type
Y/y0°/d150°
Y/y0°/d330°
Y/y180°/
d150°
Y/y180°/
d330°
Y/d30°/y180°
Voltage
phasors
Phase
shift
5–15
SETPOINTSCHAPTER 5: SETPOINTS
Table 5–1: Transformer types (Sheet 4 of 11)
Transformer
type
Y/d30°/d30°
Y/d30°/d210°
Y/d150°/y0°
Y/d150°/d30°
Y/d150°/
d210°
5–16
Wdg.
Connection
1
Voltage
phasors
Phase
shift
Transformer
type
Wdg.
Connection
WYE
30° lag
Y/d30°/d150°
1
WYE
30° lag
2
DELTA
30° lag
0°
2
DELTA
30° lag
0°
3
DELTA
30° lag
0°
3
DELTA
150° lag
240° lag
1
WYE
30° lag
1
WYE
30° lag
2
DELTA
30° lag
0°
2
DELTA
30° lag
0°
3
DELTA
210° lag
180° lag
3
DELTA
330° lag
60° lag
1
WYE
150° lag
1
WYE
150° lag
2
DELTA
150° lag
0°
2
DELTA
150° lag
0°
3
WYE
0°
150° lag
3
WYE
180° lag
330° lag
1
WYE
150° lag
1
WYE
150° lag
2
DELTA
150° lag
0°
2
DELTA
150° lag
0°
3
DELTA
30° lag
120° lag
3
DELTA
150° lag
0°
1
WYE
150° lag
1
WYE
150° lag
2
DELTA
150° lag
0°
2
DELTA
150° lag
0°
3
DELTA
210° lag
300° lag
3
DELTA
330° lag
180° lag
Y/d30°/d330°
Y/d150°/
y180°
Y/d150°/
d150°
Y/d150°/
d330°
Voltage
phasors
Phase
shift
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
Table 5–1: Transformer types (Sheet 5 of 11)
Transformer
type
Y/d210°/y0°
Y/d210°/d30°
Y/d210°/
d210°
Y/d330°/y0°
Y/d330°/d30°
Wdg.
Connection
Voltage
phasors
Phase
shift
1
WYE
210° lag
2
DELTA
210° lag
3
Wdg.
Connection
1
WYE
210° lag
0°
2
DELTA
210° lag
0°
WYE
0°
210° lag
3
WYE
180° lag
30° lag
1
WYE
210° lag
1
WYE
210° lag
2
DELTA
210° lag
0°
2
DELTA
210° lag
0°
3
DELTA
30° lag
180° lag
3
DELTA
150° lag
60° lag
1
WYE
210° lag
1
WYE
210° lag
2
DELTA
210° lag
0°
2
DELTA
210° lag
0°
3
DELTA
210° lag
0°
3
DELTA
330° lag
240° lag
1
WYE
330° lag
1
WYE
330° lag
2
DELTA
330° lag
0°
2
DELTA
330° lag
0°
3
WYE
0°
330° lag
3
WYE
180° lag
150° lag
1
WYE
330° lag
1
WYE
330° lag
2
DELTA
330° lag
0°
2
DELTA
330° lag
0°
3
DELTA
30° lag
300° lag
3
DELTA
150° lag
180° lag
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
Transformer
type
Y/d210°/
y180°
Y/d210°/
d150°
Y/d210°/
d330°
Y/d330°/
y180°
Y/d330°/
d150°
Voltage
phasors
Phase
shift
5–17
SETPOINTSCHAPTER 5: SETPOINTS
Table 5–1: Transformer types (Sheet 6 of 11)
Transformer
type
Y/d330°/
d210°
D/d0°/d0°
D/d0°/d120°
D/d0°/d240°
D/d0°/y30°
5–18
Wdg.
Connection
Voltage
phasors
Phase
shift
1
WYE
330° lag
2
DELTA
330° lag
3
Transformer
type
Wdg.
Connection
1
WYE
330° lag
0°
2
DELTA
330° lag
0°
DELTA
210° lag
120° lag
3
DELTA
330° lag
0°
1
DELTA
0°
1
DELTA
60° lag
2
DELTA
0°
0°
2
DELTA
0°
60° lag
3
DELTA
0°
0°
3
DELTA
60° lag
0°
1
DELTA
120° lag
1
DELTA
180° lag
2
DELTA
0°
120° lag
2
DELTA
0°
180° lag
3
DELTA
120° lag
0°
3
DELTA
180° lag
0°
1
DELTA
240° lag
1
DELTA
300° lag
2
DELTA
0°
240° lag
2
DELTA
0°
300° lag
3
DELTA
240° lag
0°
3
DELTA
300° lag
0°
1
DELTA
0°
1
DELTA
0°
2
DELTA
0°
0°
2
DELTA
0°
0°
3
WYE
30° lag
330° lag
3
WYE
150° lag
210° lag
Y/d330°/
d330°
D/d0°/d60°
D/d0°/d180°
D/d0°/d300°
D/d0°/y150°
Voltage
phasors
Phase
shift
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
Table 5–1: Transformer types (Sheet 7 of 11)
Transformer
type
D/d0°/y210°
D/d60°/d0°
D/d60°/d240°
D/d60°/y210°
D/d120°/
d120°
Wdg.
Connection
Voltage
phasors
Phase
shift
1
DELTA
0°
2
DELTA
0°
3
Wdg.
Connection
1
DELTA
0°
0°
2
DELTA
0°
0°
WYE
210° lag
150° lag
3
WYE
330° lag
30° lag
1
DELTA
60° lag
1
DELTA
60° lag
2
DELTA
60° lag
0°
2
DELTA
60° lag
0°
3
DELTA
0°
60° lag
3
DELTA
60° lag
0°
1
DELTA
240° lag
1
DELTA
0°
2
DELTA
60° lag
180° lag
2
DELTA
60° lag
300° lag
3
DELTA
240° lag
0°
3
WYE
30° lag
330° lag
1
DELTA
0°
1
DELTA
120° lag
2
DELTA
60° lag
300° lag
2
DELTA
120° lag
0°
3
WYE
210° lag
150° lag
3
DELTA
0°
120° lag
1
DELTA
120° lag
1
DELTA
120° lag
2
DELTA
120° lag
0°
2
DELTA
120° lag
0°
3
DELTA
120° lag
0°
3
DELTA
180° lag
300° lag
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
Transformer
type
D/d0°/y330°
D/d60°/d60°
D/d60°/y30°
D/d120°/d0°
D/d120°/
d180°
Voltage
phasors
Phase
shift
5–19
SETPOINTSCHAPTER 5: SETPOINTS
Table 5–1: Transformer types (Sheet 8 of 11)
Transformer
type
D/d120°/
y150°
D/d180°/d0°
D/d180°/
d180°
D/d180°/
y150°
D/d240°/d0°
5–20
Wdg.
Connection
Voltage
phasors
Phase
shift
1
DELTA
0°
2
DELTA
120° lag
3
Transformer
type
Wdg.
Connection
1
DELTA
0°
240° lag
2
DELTA
120° lag
240° lag
WYE
150° lag
210° lag
3
WYE
330° lag
30° lag
1
DELTA
180° lag
1
DELTA
120° lag
2
DELTA
180° lag
0°
2
DELTA
180° lag
300° lag
3
DELTA
0°
180° lag
3
DELTA
120° lag
0°
1
DELTA
0°
1
DELTA
300° lag
2
DELTA
180° lag
180° lag
2
DELTA
180° lag
120° lag
3
DELTA
180° lag
180° lag
3
DELTA
300° lag
0°
1
DELTA
0°
1
DELTA
0°
2
DELTA
180° lag
180° lag
2
DELTA
180° lag
180° lag
3
WYE
150° lag
210° lag
3
WYE
330° lag
30° lag
1
DELTA
240° lag
1
DELTA
240° lag
2
DELTA
240° lag
0°
2
DELTA
240° lag
0°
3
DELTA
0°
240° lag
3
DELTA
60° lag
180° lag
D/d120°/
y330°
D/d180°/
d120°
D/d180°/
d300°
D/d180°/
y330°
D/d240°/d60°
Voltage
phasors
Phase
shift
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
Table 5–1: Transformer types (Sheet 9 of 11)
Transformer
type
D/d240°/
d240°
D/d240°/
y210°
D/d300°/
d180°
D/y30°/d240°
D/y30°/y210°
Wdg.
Connection
1
Voltage
phasors
Phase
shift
Transformer
type
Wdg.
Connection
DELTA
240° lag
D/d240°/y30°
1
DELTA
0°
2
DELTA
240° lag
0°
2
DELTA
240° lag
120° lag
3
DELTA
240° lag
0°
3
WYE
30° lag
330° lag
1
DELTA
0°
1
DELTA
300° lag
2
DELTA
240° lag
120° lag
2
DELTA
300° lag
0°
3
WYE
210° lag
150° lag
3
DELTA
0°
300° lag
1
DELTA
300° lag
1
DELTA
0°
2
DELTA
300° lag
0°
2
WYE
30° lag
330° lag
3
DELTA
180° lag
120° lag
3
DELTA
60° lag
300° lag
1
DELTA
0°
1
DELTA
0°
2
WYE
30° lag
330° lag
2
WYE
30° lag
330° lag
3
DELTA
240° lag
120° lag
3
WYE
30° lag
330° lag
1
DELTA
0°
1
DELTA
0°
2
WYE
30° lag
330° lag
2
WYE
150° lag
210° lag
3
WYE
210° lag
150° lag
3
DELTA
0°
0°
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
D/d300°/d0°
D/y30°/d60°
D/y30°/y30°
D/y150°/d0°
Voltage
phasors
Phase
shift
5–21
SETPOINTSCHAPTER 5: SETPOINTS
Table 5–1: Transformer types (Sheet 10 of 11)
Transformer
type
D/y150°/
d120°
D/y150°/
d300°
D/y150°/
y330°
D/y210°/d60°
D/y210°/y30°
5–22
Wdg.
Connection
Voltage
phasors
Phase
shift
1
DELTA
0°
2
WYE
150° lag
3
Transformer
type
Wdg.
Connection
1
DELTA
0°
210° lag
2
WYE
150° lag
210° lag
DELTA
120° lag
240° lag
3
DELTA
180° lag
180° lag
1
DELTA
0°
1
DELTA
0°
2
WYE
150° lag
210° lag
2
WYE
150° lag
210° lag
3
DELTA
300° lag
60° lag
3
WYE
150° lag
210° lag
1
DELTA
0°
1
DELTA
0°
2
WYE
150° lag
210° lag
2
WYE
210° lag
150° lag
3
WYE
330° lag
30° lag
3
DELTA
0°
0°
1
DELTA
0°
1
DELTA
0°
2
WYE
210° lag
150° lag
2
WYE
210° lag
150° lag
3
DELTA
60° lag
300° lag
3
DELTA
240° lag
120° lag
1
DELTA
0°
1
DELTA
0°
2
WYE
210° lag
150° lag
2
WYE
210° lag
150° lag
3
WYE
30° lag
330° lag
3
WYE
210° lag
150° lag
D/y150°/
d180°
D/y150°/
y150°
D/y210°/d0°
D/y210°/
d240°
D/y210°/
y210°
Voltage
phasors
Phase
shift
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
Table 5–1: Transformer types (Sheet 11 of 11)
Transformer
type
D/y330°/d0°
D/y330°/
d180°
D/y330°/
y150°
Y/z30°/z30°
Wdg.
Connection
Voltage
phasors
Phase
shift
1
DELTA
0°
2
WYE
330° lag
3
Wdg.
Connection
1
DELTA
0°
30° lag
2
WYE
330° lag
30° lag
DELTA
0°
0°
3
DELTA
120° lag
240° lag
1
DELTA
0°
1
DELTA
0°
2
WYE
330° lag
30° lag
2
WYE
330° lag
30° lag
3
DELTA
180° lag
180° lag
3
DELTA
300° lag
60° lag
1
DELTA
0°
1
DELTA
0°
2
WYE
330° lag
30° lag
2
WYE
330° lag
30° lag
3
WYE
150° lag
210° lag
3
WYE
330° lag
30° lag
1
WYE
30° lag
1
WYE
0°
2
ZIG-ZAG
30° lag
0°
2
WYE
0°
0°
3
ZIG-ZAG
30° lag
0°
3
WYE
0°
0°
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
Transformer
type
D/y330°/
d120°
D/y330°/
d300°
D/y330°/
y330°
Y/y0°/y0°
Voltage
phasors
Phase
shift
5–23
SETPOINTSCHAPTER 5: SETPOINTS
5.2.7
Phase Shifts
The table below provides additional information about the Phase shift column in Table 5–
1: Transformer types on page 5–13 and represents an assumed ABC phasor rotation. For
transformers connected to a system with a phasor rotation of ACB, interchange all B (b)
and C (c) designations.
Table 5–2: Phase shifts
Phase shift
0°
30° lag
a=A
b=B
c=C
a = (A – C) /
3
b = (B – A) /
3
c = (C – B) /
3
60° lag
a = –C
b = –A
c = –B
90° lag
a = (B – C) /
3
b = (C – A) /
3
c = (A – B) /
3
120° lag
150° lag
a=B
b=C
c=A
a = (B – A) /
3
b = (C – B) /
3
c = (A – C) /
3
180° lag
a = –A
b = –B
c = –C
210° lag
a = (C – A) /
3
b = (A – B) /
3
c = (B – C) /
3
240° lag
270° lag
300° lag
330° lag
5–24
Input phasors Output phasors Phasor transformation
a=C
b=A
c=B
a = (C – B) /
3
b = (A – C) /
3
c = (B – A) /
3
a = –B
b = –C
c = –A
a = (A – B) /
3
b = (B – C) /
3
c = (C – A) /
3
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
5.3
S1 745 setup
5.3.1
Passcode
PATH: SETPOINTS Z S1 745 SETUP Z PASSCODE
„ PASSCODE
SETPOINT ACCESS:
Read & Write
Range:
1 to 8 numeric digits
MESSAGE
RESTRICT SETPOINT
WRITE ACCESS? No
Range:
No, Yes
MESSAGE
ALLOW SETPOINT
WRITE ACCESS? No
Range:
No, Yes
MESSAGE
CHANGE PASSCODE?
No
Range:
No, Yes
MESSAGE
ENCRYPTED PASSCODE:
AIKFBAIK
Range:
factory default passcode is “0”
[ Z]
After installing the setpoint access jumper, a passcode must be entered (if the passcode
security feature is enabled) before setpoints can be changed. When the 745 is shipped
from the factory, the passcode is defaulted to 0. When the passcode is 0, the passcode
security feature is disabled and only the setpoint access jumper is required for changing
setpoints from the front panel. Passcode entry is also required when programming
setpoints from any of the serial communication ports.
5.3.2
•
SETPOINT ACCESS: This setpoint cannot be edited directly. It indicates if passcode
protection is enabled (“Read Only”) or disabled (“Read & Write”).
•
RESTRICT SETPOINT WRITE ACCESS: This setpoint is only displayed when setpoint
write access is allowed and the current passcode is not “0”. Select “Yes” and follow
directions to restrict write access. This message is replaced by ALLOW SETPOINT
WRITE ACCESS when write access is restricted.
•
ALLOW SETPOINT WRITE ACCESS: This setpoint is displayed when setpoint write
access is restricted. New setpoints cannot be entered in this state. To gain write
access, select “Yes” and enter the previously programmed passcode. If the passcode
is correctly entered, new setpoint entry is allowed. If there is no keypress within 30
minutes, setpoint write access is automatically restricted. As an additional safety
measure, the SELF-TEST ERROR: Access Denied message is generated when the
passcode is entered incorrectly three consecutive times.
•
CHANGE PASSCODE: Select “Yes” and follow directions to change the current
passcode. Changing the passcode to the factory default of “0” disables the passcode
security feature.
•
ENCRYPTED PASSCODE: If the programmed passcode is unknown, consult the factory
service department with the encrypted passcode. The passcode can be determined
using a deciphering program.
Preferences
PATH: SETPOINTS Z S1 745 SETUP ZV PREFERENCES
„ PREFERENCES
[ Z]
FLASH MESSAGE TIME:
4.0 s
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
Range:
0.5 to 10.0 s in steps of 0.5
5–25
SETPOINTSCHAPTER 5: SETPOINTS
MESSAGE
DEFAULT MESSAGE
TIMEOUT: 300 s
Range:
10 to 900 s in steps of 1
Some relay characteristics can be modified to accommodate the user preferences. This
section allows for the definition of such characteristics.
5.3.3
•
FLASH MESSAGE TIME: Flash messages are status, warning, error, or information
messages displayed for several seconds, in response to certain key presses during
setpoint programming. The time these messages remain on the display, overriding the
normal messages, can be changed to accommodate different user reading rates.
•
DEFAULT MESSAGE TIMEOUT: After this period of time of no activity on the keys, the
745 automatically begins to display the programmed set of default messages
programmed in S1 745 SETUP ZV DEFAULT MESSAGES.
Communications
5.3.3.1 Main Menu
PATH: SETPOINTS Z S1 745 SETUP ZV COMMUNICATIONS
„ COMMUNICATIONS [Z]
„ PORT SETUP
MESSAGE
MESSAGE
„ DNP
[ Z]
[ Z]
„ NETWORK SETUP [Z]
See below.
See page 5–27
See page 5–28
The NETWORK SETUP menu is seen only if the Ethernet option is ordered.
5.3.3.2 Port Setup
PATH: SETPOINTS Z S1 745 SETUP ZV COMMUNICATIONS Z PORT SETUP
„ PORT SETUP
5–26
SLAVE ADDRESS:
254
Range:
1 to 254 in steps of 1
MESSAGE
COM1 BAUD RATE:
19200 Baud
Range:
300, 1200, 2400, 4800, 9600,
19200 Baud
MESSAGE
COM1 PARITY:
None
Range:
None, Even, Odd
MESSAGE
COM1 HARDWARE:
RS485
Range:
RS485, RS422
MESSAGE
COM2 BAUD RATE:
19200 Baud
Range:
300, 1200, 2400, 4800, 9600,
19200 Baud
MESSAGE
COM2 PARITY:
None
Range:
None, Even, Odd
MESSAGE
FRONT BAUD RATE:
19200 Baud
Range:
300, 1200, 2400, 4800, 9600,
19200 Baud
MESSAGE
FRONT PARITY:
None
Range:
None, Even, Odd
[ Z]
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
Up to 32 relays can be daisy-chained and connected to a computer or a programmable
controller, using either the two-wire RS485 or the four-wire RS422 serial communication
port at the rear of the 745. Before using communications, each relay must be programmed
with a unique address and a common baud rate.
•
SLAVE ADDRESS: Enter a unique address, from 1 to 254, for this particular relay on
both COM1 and COM2 serial communication links. Although addresses need not be
sequential, no two relays can have the same address. Generally each relay added to
the link will use the next higher address, starting from address 1. No address is
required to use the front panel program port since only one relay can be connected at
one time.
•
COM1/COM2 BAUD RATE: Select the baud rates for COM1, the RS485/RS422
communication port, or COM2. All relays on the communication link, and the
computer connecting them, must run at the same baud rate. The fastest response is
obtained at 19200 baud.
•
COM1/COM2 PARITY: The data frame is fixed at 1 start, 8 data, and 1 stop bit. If
required, a parity bit is programmable. The parity of the transmitted signal must
match the parity displayed in this setpoint.
•
COM1 HARDWARE: If the two-wire RS485 hardware configuration is required for the
COM1 serial communication port, select RS485. If the four wire RS422 hardware
configuration is required, select RS422.
•
FRONT BAUD RATE / FRONT PARITY: Select the baud rate / parity for the front panel
port.
5.3.3.3 DNP Communications
PATH: SETPOINTS Z S1 745 SETUP ZV COMMUNICATIONS ZV DNP
„ DNP
DNP PORT:
None
Range:
None, COM1, COM2, Front
MESSAGE
DNP POINT MAPPING:
Enabled
Range:
Enabled, Disabled
MESSAGE
TRANSMISSION DELAY:
0 ms
Range:
0 to 65000 ms in steps of 1
MESSAGE
DATA LINK CONFIRM
MODE: Never
Range:
Never, Always, Sometimes
MESSAGE
DATA LINK CONFIRM
TIMEOUT: 1000 ms
Range:
1 to 65000 ms in steps of 1
MESSAGE
DATA LINK CONFIRM
RETRIES: 3
Range:
0 to 100 in steps of 1
MESSAGE
SELECT/OPERATE ARM
TIMEOUT: 10000 ms
Range:
1 to 65000 ms in steps of 1
MESSAGE
WRITE TIME INTERVAL:
0 ms
Range:
0 to 65000 ms in steps of 1
MESSAGE
COLD RESTART
INHIBIT: Disabled
Range:
Enabled, Disabled
[Z]
•
DNP PORT: Selects the communication port for DNP communications.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–27
SETPOINTSCHAPTER 5: SETPOINTS
•
DNP POINT MAPPING: When enabled, the 120 User Map Values are included in the
DNP Object 30 point list. For additional information, refer to GE Multilin publication
number GEK-106636A: 745 Communications Guide.
•
TRANSMISSION DELAY: Select the minimum time from when a DNP request is received
and a response issued. A value of zero causes the response to be issued as quickly as
possible.
•
DATA LINK CONFIRM MODE: Select the data link confirmation mode for responses
sent by the 745. When “Sometimes” is selected, data link confirmation is only
requested when the response contains more than one frame.
•
DATA LINK CONFIRM TIMEOUT: Selects a desired timeout. If no confirmation response
is received within this time, the 745 will re-send the frame if retries are still available.
•
DATA LINK CONFIRM RETRIES: Select the maximum number of retries that will be
issued for a given data link frame.
•
SELECT/OPERATE ARM TIMEOUT: Select the duration of the select / operate arm timer.
•
WRITE TIME INTERVAL: Select the time that must elapse before the 745 will set the
‘need time’ internal indication (IIN). After the time is written by a DNP master, the IIN
will be set again after this time elapses. A value of zero disables this feature.
•
COLD RESTART INHIBIT: When disabled, a cold restart request from a DNP master will
cause the 745 to be reset. Enabling this setpoint will cause the cold restart request to
initialize only the DNP sub-module.
When “Disabled” is selected, a cold restart request will cause loss of protection until
the 745 reset completes.
5.3.3.4 Network Setup
PATH: SETPOINTS Z S1 745 SETUP ZV COMMUNICATIONS ZV NETWORK SETUP
IP ADDRESS:
0.0.0.0
Range:
standard IP address format
MESSAGE
SUBNET IP MASK:
255.255.255.000
Range:
standard IP address format
MESSAGE
GATEWAY IP ADDRESS:
0.0.0.0
Range:
standard IP address format
„ NETWORK SETUP [Z]
The IP addresses are used with the Modbus protocol. Enter the dedicated IP, subnet IP, and
gateway IP addresses provided by the network administrator.
To ensure optimal response from the relay, the typical connection timeout should be set as
indicated in the following table:
TCP/IP sessions
5–28
Timeout setting
up to 2
2 seconds
up to 4
3 seconds
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
5.3.4
Resetting
PATH: SETPOINTS Z S1 745 SETUP ZV RESETTING
„ RESETTING
[Z]
MESSAGE
LOCAL RESET
BLOCK: Disabled
Range:
Enabled, Disabled
REMOTE RESET
SIGNAL: Disabled
Range:
Enabled, Disabled
The reset function performs the following actions: all latched relays are set to the nonoperated state and latched target messages are cleared, if the initiating conditions are no
longer present. Resetting can be performed in any of the following ways: via RESET on the
front panel while the 745 is in local mode (i.e. the Local LED indicator is on); via a logic input;
via any of the communication ports.
5.3.5
•
LOCAL RESET BLOCK: The 745 is defaulted to the local mode. As a result, the front
panel (local) RESET key is normally operational. Select any logic input, virtual input,
output relay, or virtual output which, when asserted or operated, will block local mode,
and hence the operation of the front panel RESET.
•
REMOTE RESET SIGNAL: Select any logic input which, when asserted, will (remotely)
cause a reset command.
Clock
PATH: SETPOINTS Z S1 745 SETUP ZV CLOCK
„ CLOCK
DATE (MM/DD/YYYY):
01/01/1996
Range:
1 to 12 / 1 to 31 / 1990 to 2089
MESSAGE
TIME (HH:MM:SS):
00:00:00
Range:
0 to 23 : 0 to 59 : 0 to 59
MESSAGE
IRIG-B SIGNAL TYPE:
None
Range:
None, DC Shift, Amplitude
Modulated
[Z]
~
The 745 includes a battery-backed internal clock that runs even when control power is
lost. Battery power is used only when the 745 is not powered. The battery is rated to last
for at least 10 years continuous use. The clock is accurate to within 1 minute per month. An
IRIG-B signal may be connected to the 745 to synchronize the clock to a known time base
and to other relays. The clock performs time and date stamping for various relay features,
such as event and last trip data recording. Without an IRIG-B signal, the current time and
date must be entered in a new relay for any time and date displayed. If not entered, all
message references to time or date will display “Unavailable”. With an IRIG-B signal, only
the current year needs to be entered.
•
DATE: Enter the current date, using two digits for the month, two digits for the day,
and four digits for the year. For example, April 30, 1996 would be entered as “04 30
1996”. If entered from the front panel, the new date will take effect at the moment of
pressing the ENTER key.
•
TIME: Enter the current time by using two digits for the hour in 24 hour time, two digits
for the minutes, and two digits for the seconds. The new time takes effect at the
moment of pressing the ENTER key. For example, 3:05 PM is entered as “15 05 00”, with
the ENTER key pressed at exactly 3:05 PM.
•
IRIG-B SIGNAL TYPE: Select the type of IRIG-B signal being used for clock
synchronization. Select “None” if no IRIG-B signal is to be used.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–29
SETPOINTSCHAPTER 5: SETPOINTS
5.3.6
Default Messages
PATH: SETPOINTS Z S1 745 SETUP ZV DEFAULT MESSAGES
„ DEFAULT
[ Z]
1 MESSAGES SELECTED
29 REMAIN UNASSIGNED
MESSAGES
MESSAGE
745 Transformer
Management Relay
Range:
cannot be edited
Range:
Press decimal, ENTER, ENTER
at any message to select as a
default message.
Under normal conditions, if no front panel keys have been pressed for longer than the time
specified in S1 745 SETUP ZV PREFERENCES ZV DEFAULT MESSAGE TIMEOUT, the screen
begins to sequentially display up to thirty (30) user-selected default messages. In addition,
up to 5 user programmable text messages can be assigned as default messages. For
example, the relay could be set to sequentially display a text message identifying the
transformer, the system status, the measured current in each phase, and the harmonic
inhibit level. Currently selected default messages are viewed under S1 745 SETUP ZV
DEFAULT MESSAGES. The first message in this section states the number of messages
currently selected.
Default messages are added to the end of the default message list as follows:
Z Allow access to setpoints by installing the setpoint access jumper and
entering the correct passcode.
Z Select the setpoint or actual value message to be entered as a default
message, so that it is displayed.
If user text is required, go into S1 745 SETUP ZV SCRATCHPAD and edit
the text for default.
Z Press the decimal key followed by ENTER while the message is
displayed.
The screen will display PRESS [ENTER] TO ADD AS DEFAULT.
Z Press ENTER again while this message is being displayed.
The message is now added to the default message list.
Default messages are removed from the default message list as follows:
Z Allow access to setpoints by installing the setpoint access jumper and
entering the correct passcode.
Z Select the message under the section S1 745 SETUP ZV DEFAULT
MESSAGES to remove from the default message list.
Z Press the decimal key followed by ENTER.
The screen displays PRESS [ENTER] TO REMOVE MESSAGE.
Z Press ENTER while this message is being displayed.
The message is now removed from the default message list and the
messages that follow are moved up to fill the gap.
5–30
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
5.3.7
Scratchpad
PATH: SETPOINTS Z S1 745 SETUP ZV SCRATCHPAD
„ SCRATCHPAD
[ Z]
MESSAGE
Text 1
Range:
Up to forty (40) alphanumeric
characters
Text 2
Range:
Up to forty (40) alphanumeric
characters
Range:
Up to forty (40) alphanumeric
characters
↓
MESSAGE
Text 5
Up to five (5) message screens can be programmed and selected as default messages.
These messages can be used to provide identification information about the system or
instructions to operators.
•
5.3.8
TEXT 1 to TEXT 5: Press ENTER to begin editing scratchpad messages 1 through 5. The
text may be changed from “Text 1" one character at a time, using the VALUE keys.
Press the ENTER key to store the edit and advance to the next character position. This
message may then be stored as a default message.
Installation
PATH: SETPOINTS Z S1 745 SETUP ZV INSTALLATION
„ INSTALLATION [Z]
745 SETPOINTS:
Not Programmed
Range:
Programmed,
Not Programmed
To safeguard against the installation of a relay whose setpoints have not been entered, the
745 will not allow signaling of any output relay, will have the In Service LED off and the SelfTest Error LED on, until the 745 is set to “Programmed”. The setpoint is defaulted to “Not
Programmed” when the relay leaves the factory. The SETPOINTS HAVE NOT BEEN
PROGRAMMED self-test error message is displayed automatically until the 745 is put into
the programmed state:
5.3.9
Upgrade Options
PATH: SETPOINTS Z S1 745 SETUP ZV UPGRADE OPTIONS
ENABLE ANALOG I/O?
Yes
Range:
Yes, No
MESSAGE
ENABLE LOSS OF LIFE?
Yes
Range:
Yes, No
MESSAGE
ENABLE RESTRICTED
GROUND FAULT? Yes
Range:
Yes, No
ENTER PASSCODE:
Range:
Enter the passcode supplied by
the manufacturer
UPGRADE OPTIONS?
Yes
Range:
Yes, No
„ UPGRADE OPTIONS [Z]
MESSAGE
MESSAGE
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–31
SETPOINTSCHAPTER 5: SETPOINTS
Some options may be added while the relay is in the field. These include the analog input/
output, loss of life and restricted ground fault options. Should this be desired, contact the
factory with the 745 order code and serial number (see A4 PRODUCT INFO ZV REVISION
CODES ZV INSTALLED OPTIONS and SERIAL NUMBER) and the new option(s) to be added.
The factory will supply a passcode that may be used to add the new options to the 745.
Before entering the passcode and performing the upgrade, it is important to set the
ENABLE setpoints correctly (see descriptions below). Any options that are currently
supported by the 745 as well as any options that are to be added should have the
corresponding ENABLE setpoint set to “Yes”. All others must be set to “No”.
For example, if the 745 currently supports only the analog input/output option and the loss
of life option is to be added, then the ENABLE ANALOG I/O setpoint and the ENABLE LOSS OF
LIFE setpoint must be set to “Yes”. The ENABLE RESTRICTED GROUND FAULT setpoint must
be set to “No”.
5–32
•
ENABLE ANALOG I/O: Select “Yes” if the upgrade options set supports the analog
input/output feature, otherwise select “No”. The default value for this setpoint reflects
the current state of the option.
•
ENABLE LOSS OF LIFE: Select “Yes” if the upgrade options set supports the loss of life
feature and select “No” otherwise. The default value for this setpoint reflects the
current state of the option.
•
ENABLE RESTRICTED GROUND FAULT: Select “Yes” if the upgrade options set
supports the restricted ground fault feature and select “No” otherwise. The default
value for this setpoint reflects the current state of the option.
•
ENTER PASSCODE: Press ENTER to begin entering the factory-supplied upgrade
passcode. This setpoint has a textual format, thus it is edited in the same manner as,
for example, the setpoints under S1 745 SETUP ZV SCRATCHPAD.
•
UPGRADE OPTIONS: When all of the above setpoints are properly programmed, select
“Yes” and press ENTER to prompt the 745 to upgrade its options. A flash message
appears indicating the results of the upgrade. A successful upgrade may be verified
by examining A4 PRODUCT INFO ZV REVISION CODES ZV INSTALLED OPTIONS.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
5.3.10 Setup Event Recorder
PATH: SETPOINTS Z S1 745 SETUP ZV SETUP EVENT RECORDER
„ SETUP EVENT
PICKUP EVENT:
Enabled
Range:
Enabled, Disabled
MESSAGE
OPERATE EVENT:
Enabled
Range:
Enabled, Disabled
MESSAGE
DROPOUT EVENT:
Enabled
Range:
Enabled, Disabled
MESSAGE
ERROR EVENT:
Enabled
Range:
Enabled, Disabled
MESSAGE
OFF EVENT:
Enabled
Range:
Enabled, Disabled
MESSAGE
ON EVENT:
Enabled
Range:
Enabled, Disabled
[ Z]
RECORDER
These setpoints allow the user to configure the event recorder by enabling/disabling the
event types indicated.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–33
SETPOINTSCHAPTER 5: SETPOINTS
5.4
S2 System Setup
5.4.1
Description
This group of setpoints is critical for the protection features to operate correctly. When the
relay is ordered, the phase and ground CT inputs must be specified as either 5 A or 1 A. The
characteristics of the equipment installed on the system are entered on this page. This
includes information on the transformer type, CTs, VT, ambient temperature sensor, onload
tap changer, demand metering, analog outputs and analog input.
5.4.2
Transformer
PATH: SETPOINTS ZV S2 SYSTEM SETUP Z TRANSFORMER
„ TRANSFORMER
NOMINAL FREQUENCY:
60 Hz
Range:
50 Hz, 60 Hz
MESSAGE
FREQUENCY TRACKING:
Enabled
Range:
Enabled, Disabled
MESSAGE
PHASE SEQUENCE:
ABC
Range:
ABC, ACB
MESSAGE
TRANSFORMER TYPE:
Y/d30°
Range:
Refer to Transformer types on
page 5–13
MESSAGE
LOAD LOSS AT RATED
LOAD: 1250 kW
Range:
0 to 20000 kW in steps of 1
(Auto-ranging; see table below)
MESSAGE
LOW VOLTAGE WINDING
RATING: Above 5 kV
Range:
Above 5 kV, 1 kV to 5 kV, Below
1 kV
MESSAGE
RATED WINDING TEMP
RISE: 65°C (oil)
Range:
65°C (oil), 55°C (oil), 80°C (dry),
115°C (dry), 150°C (dry)
MESSAGE
NO-LOAD LOSS:
125.0 kW
Range:
0.1 to 2000.0 kW in steps of 0.1
(see description below)
MESSAGE
TYPE OF COOLING:
OA
Range:
FA, OA, Directed FOA/FOW,
Non-Directed FOA/FOW
MESSAGE
RATED TOP OIL RISE
OVER AMBIENT: 10°C
Range:
1 to 200°C in steps of 1
MESSAGE
XFMR THRML CAPACITY:
1.00 kWh/°C
Range:
0.00 to 200.00 kWh/°C in steps
of 0.01
MESSAGE
WINDING TIME CONST:
2.00 min.
Range:
0.25 to 15.00 min. in steps of
0.01
MESSAGE
SET ACCUMULATED LOSS
OF LIFE: 0 x 10h
Range:
0 to 20000 x 10h in steps of 1
[Z]
To provide accurate and effective transformer protection, the parameters of both the
transformer and the system configuration must be supplied to the 745 relay.
•
5–34
NOMINAL FREQUENCY: Enter the nominal frequency of the power system. This
setpoint is used to determine the sampling rate in the absence of a measurable
frequency. Frequency is measured from the VT input when available. If the VT input is
not available, current from Winding 1 Phase A is used.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
•
FREQUENCY TRACKING: In situations where the AC signals contain significant amount
of sub-harmonic components, it may be necessary to disable frequency tracking.
•
PHASE SEQUENCE: Enter the phase sequence of the power system. Systems with an
ACB phase sequence require special considerations. See Phase Shifts on Three-phase
Transformers on page 5–8 for details.
•
TRANSFORMER TYPE: Enter the transformer connection from the table of transformer
types. Phase correction and zero-sequence removal are performed automatically as
required.
If TRANSFORMER TYPE is entered as “2W External Correction” or “3W External Correction”
with a delta/wye power transformer, the WINDING 1(3) PHASE CT PRIMARY setting values
must be divided by 3 on the delta current transformer side to compensate the current
magnitude. With this correction, the 745 will properly compare line to neutral currents on
all sides of the power transformer.
For example, for a two-winding delta/wye power transformer with wye-connected current
transformers on the delta side of the power transformer (25000:5 ratio), and deltaconnected current transformers on the wye side of the transformer (4000:5 ratio), set:
TRANSFORMER TYPE: “2W External Connection”
WINDING 1 PHASE CT PRIMARY: “25000:5”
WINDING 2 PHASE CT PRIMARY: (4000 / 3 ):5 or “2309:5”
•
LOAD LOSS AT RATED LOAD: Enter the load loss at rated load. This value is used for
calculation of harmonic derating factor, and in the Insulating Aging function. This is an
auto-ranging setpoint dependent on the LOW VOLTAGE WINDING RATING value; see
ranges in the following table
Setting
Low voltage winding rating
above 5 kV
1 kV to 5 kV
MINIMUM TAP
POSITION VOLTAGE
0.1 to 2000.0 kV
in steps of 0.1
0.01 to 200.00 kV
in steps of 0.01
0.001 to 20.000 kV
in steps of 0.001
below 1 kV
VOLTAGE
INCREMENT PER TAP
0.01 to 20.00 kV
in steps of 0.01
0.001 to 2.000 kV
in steps of 0.001
0.0001 to 0.2000 kV
in steps of 0.0001
LOAD LOSS AT
RATED LOAD
1 to 20000 kW
in steps of 0.1
0.1 to 2000.0 kW
in steps of 0.01
0.01 to 200.00 kW
in steps of 0.001
NO LOAD LOSS
0.1 to 2000.0 kW
in steps of 1
0.01 to 200.00 kW
in steps of 0.1
0.001 to 20.000 kW in
steps of 0.01
•
LOW VOLTAGE WINDING RATING: Enter the low voltage winding rating. This selection
affects the ranges of WINDING 1(3) NOM ø-ø VOLTAGE, WINDING 1(3) RATED LOAD,
MINIMUM TAP POSITION VOLTAGE, and VOLTAGE INCREMENT PER TAP as shown in the
table above.
•
RATED WINDING TEMP RISE: Determines the type of insulation; for use in the
computation of insulation aging.
•
NO-LOAD LOSS: From the transformer data. It is required for insulation aging
calculations This is an auto-ranging setpoint dependent on the LOW VOLTAGE
WINDING RATING value; see ranges in the above table.
•
TYPE OF COOLING: From Transformer data; required for insulation aging calculations.
•
RATED TOP OIL RISE OVER AMBIENT: Required for insulation aging calculations
•
XFMR THRML CAPACITY: Required for insulation aging calculations. Obtain from
transformer manufacturer
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–35
SETPOINTSCHAPTER 5: SETPOINTS
5.4.3
•
WINDING TIME CONST: Required for insulation aging calculations
•
SET ACCUMULATED LOSS OF LIFE: Required for insulation aging calculations. Set
equal to the estimated accumulated loss of life.
Windings 1 to 3
PATH: SETPOINTS ZV S2 SYSTEM SETUP ZV WINDING 1(3)
„ WINDING 1
WINDING 1 NOM Φ-Φ
VOLTAGE: 220.0 kV
Range:
Dependent on LOW VOLTAGE
WINDING RATING; see below.
MESSAGE
WINDING 1 RATED
LOAD: 100.0 MVA
Range:
Dependent on LOW VOLTAGE
WINDING RATING; see below.
MESSAGE
WINDING 1 PHASE CT
PRIMARY: 500:5 A
Range:
1 to 50000:5 A in steps of 1
MESSAGE
WINDING 1 GROUND CT
INPUT: NONE
Range:
None, G1/2, G2/3
MESSAGE
WINDING 1 GROUND CT
PRIMARY: 2000:1 A
Range:
1 to 50000:1 A in steps of 1
MESSAGE
WINDING 1 SERIES 3Φ
RESISTANCE: 10.700 Ω
Range:
0.001 to 50.000 Ω in steps of
0.001
[ Z]
These setpoints describe the characteristics of each transformer winding and the CTs
connected to them.
Note
The above setpoint options are also available for the second and third winding. Winding 3
setpoints are only visible if the unit has the appropriate hardware and if the selected
TRANSFORMER TYPE is a three-winding transformer.
•
WINDING 1(3) NOM Φ−Φ VOLTAGE: Enter the nominal phase-to-phase voltage rating
of Winding 1(3) of the transformer. The range for this setpoint is affected by the S2
SYSTEM SETUP Z TRANSFORMER ZV LOW VOLTAGE WINDING RATING setting (see table
below).
•
WINDING 1(3) RATED LOAD: Enter the self-cooled load rating for winding 1(3) of the
transformer. The range for this setpoint is affected by the S2 SYSTEM SETUP Z
TRANSFORMER ZV LOW VOLTAGE WINDING RATING setting (see the table below).
Setting
5–36
Low voltage winding rating value
above 5 kV
1 kV to 5 kV
below 1 kV
WINDING 1(3) NOM Φ-Φ
VOLTAGE
0.1 to 2000.0 kV in
steps of 0.1
0.01 to 200.00 kV in
steps of 0.01
0.001 to 20.000 kV
in steps of 0.001
WINDING 1(3) RATED
LOAD
0.1 to 2000.0 MVA
in steps of 0.1
0.01 to 200.00 MVA
in steps of 0.01
0.001 to 20.000
MVA in steps of
0.001
•
WINDING 1(3) PHASE CT PRIMARY: Enter the phase CT primary current rating of the
current transformers connected to winding 1(3). The CT secondary current rating must
match the relay phase current input rating indicated.
•
WINDING 1(3) GROUND INPUT SELECTION: Select the ground CT (G1/2 or G2/3) for
the particular winding required. Leave ground CT selection at default value of "None" if
no CT is needed on the required winding.
The ground input selection settings will be defaulted to "None" when an upgrade
settings file is uploaded.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
This setting is visible only for a 3W transformer.
Note
Whenever transformer type is changed (particularly from 2 W to 3 W) "ground input
selection" setting should be cross-checked.
Note
5.4.4
•
WINDING 1(3) GROUND CT PRIMARY: Enter the ground CT primary current rating of
the current transformers connected in the winding 1(3) neutral to ground path. The CT
secondary current rating must match the relay ground current input rating indicated.
•
WINDING 1(3) SERIES 3-Φ RESISTANCE: Enter the series three-phase resistance of the
winding (that is, the sum of the resistance of each of the three phases for the winding).
This value is normally only available from the transformer manufacturer’s test report,
and is used in the 745 for calculation of harmonic derating factor.
Onload Tap Changer
PATH: SETPOINTS ZV S2 SYSTEM SETUP ZV ONLOAD TAP CHANGER
„ ONLOAD TAP
WINDING WITH TAP
CHANGER: None
Range:
None, Winding 1, Winding 2,
Winding 3
MESSAGE
NUMBER OF TAP
POSITIONS: 33
Range:
2 to 50 in steps of 1
MESSAGE
MINIMUM TAP POSITION
VOLTAGE: 61.0 kV
Range:
Dependent on LOW VOLTAGE
WINDING RATING; see below.
MESSAGE
VOLTAGE INCREMENT
PER TAP: 0.50 kV
Range:
Dependent on LOW VOLTAGE
WINDING RATING; see below.
MESSAGE
RESISTANCE INCREMENT
PER TAP: 33 Ω
Range:
10 to 500 Ω in steps of 1
[ Z]
CHANGER
This section contains the settings to configure the tap position input. The 745 accepts a
resistive input from the tap changer control circuitry, which is used in the 745 to
dynamically correct for CT ratio mismatch based on the dynamically changing voltage
ratio of the transformer. Thus, the percent differential function of the device can be set for
greater sensitivity. See Dynamic CT Ratio Mismatch Correction on page 5–6 for more details
on the tap position input.
•
WINDING WITH TAP CHANGER: Enter the winding with the tap changer. Enter 'None'
for a transformer with no onload tap changer, or to disable this feature.
•
NUMBER OF TAP POSITIONS: Enter the number of tap positions here.
•
MINIMUM TAP POSITION VOLTAGE: Enter the voltage at the lowest tap position. This is
an auto-ranging setpoint dependent on S2 SYSTEM SETUP Z TRANSFORMER ZV LOW
VOLTAGE WINDING RATING; see ranges in the table below.
•
VOLTAGE INCREMENT PER TAP: Enter the voltage increment for each tap. The range is
affected by the setpoint. This is an auto-ranging setpoint dependent on the S2 SYSTEM
SETUP Z TRANSFORMER ZV LOW VOLTAGE WINDING RATING value; see ranges in the
following table:
Setting
MINIMUM TAP POSITION
VOLTAGE
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
Low voltage winding rating value
above 5 kV
1 kV to 5 kV
below 1 kV
0.1 to 2000.0 kV in
steps of 0.1
0.01 to 200.00 kV in
steps of 0.01
0.001 to 20.000 kV
in steps of 0.001
5–37
SETPOINTSCHAPTER 5: SETPOINTS
Setting
Low voltage winding rating value
VOLTAGE INCREMENT
PER TAP
•
5.4.5
above 5 kV
1 kV to 5 kV
below 1 kV
0.01 to 20.00 kV in
steps of 0.01
0.001 to 2.000 kV in
steps of 0.001
0.0001 to 0.2000 kV
in steps of 0.0001
RESISTANCE INCREMENT PER TAP: Enter the resistance increment that the 745 will see
for each tap increment. The maximum resistance value for the top tap is 5 KΩ.
Harmonics
PATH: SETPOINTS ZV S2 SYSTEM SETUP ZV HARMONICS
„ HARMONICS
HARMONIC DERATING
ESTIMATION: Disabled
Range:
Enabled, Disabled
MESSAGE
THD MINIMUM HARMONIC
NUMBER: 2nd
Range:
2nd, 3rd, 4th,..., 21st
MESSAGE
THD MAXIMUM HARMONIC
NUMBER: 2nd
Range:
2nd, 3rd, 4th,..., 21st
[Z]
The 745 calculates the individual harmonics in each of the phase current inputs up to the
21st harmonic. With this information, it calculates an estimate of the effect of nonsinusoidal load currents on the transformer rated full load current. These calculations are
based on ANSI/IEEE Standard C57.110-1986, and require information that is often only
available from the transformer manufacturer’s test report, including the three-phase
resistance of each winding and the load loss at rated load. The harmonic derating factor
will only be valid if this information has been entered correctly.
The 745 also calculates the total harmonic distortion of the phase current input signals.
The band of frequencies over which this calculation is made can be changed to be more
selective than the default 2nd to 21st harmonics.
5.4.6
•
HARMONIC DERATING FUNCTION: Enter “Enabled” to enable the harmonic derating
factor calculations.
•
THD MINIMUM/MAXIMUM HARMONIC NUMBER Enter the minimum/maximum
harmonic number of the frequency band over which total harmonic distortion is
calculated.
FlexCurves™
PATH: SETPOINTS ZV S2 SYSTEM SETUP ZV FLEXCURVES Z FLEXCURVE A(C)
„ FLEXCURVE A
[ Z]
MESSAGE
FLEXCURVE A DELAY AT
1.03 x PU: 0 ms
Range:
0 to 65000 ms in steps of 1
FLEXCURVE A DELAY AT
1.05 x pu: 0 ms
Range:
0 to 65000 ms in steps of 1
Range:
0 to 65000 ms in steps of 1
↓
MESSAGE
FLEXCURVE A DELAY AT
20.0 x pu: 0 ms
Three programmed custom FlexCurves™ can be stored in the 745 as FlexCurve™ A,
FlexCurve™ B, and FlexCurve™ C. This allows the user to save special curves for specific
applications and then select them as required for time overcurrent element curves. The
5–38
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
custom FlexCurve™ has setpoints for entering the times-to-trip at various levels of pickup.
The levels are as follows: 1.03, 1.05, 1.1 to 6.0 × pu in steps of 0.1, and 6.5 to 20.0 × pu in
steps of 0.5.
•
5.4.7
FLEXCURVE A DELAY AT n × PU: Enter the trip time for n = 1.03. 1.05,..., 20.0 × pu for
FlexCurve™ A(C). The messages that follow sequentially correspond to the trip times
for the various pickup levels as indicated above.
Voltage Input
PATH: SETPOINTS ZV S2 SYSTEM SETUP ZV VOLTAGE INPUT
VOLTAGE SENSING:
Disabled
Range:
Enabled, Disabled
MESSAGE
VOLTAGE INPUT
PARAMETER: W1 Van
Range:
W1, W2, W3;
Van, Vbn, Vcn, Vab, Vbc, Vca
MESSAGE
NOMINAL VT SECONDARY
VOLTAGE: 120.0 V
Range:
60.0 to 120.0 in steps of 0.1
MESSAGE
VT RATIO:
1000:1
Range:
1 to 5000:1 in steps of 1
„ VOLTAGE INPUT [Z]
The 745 provides a voltage input for the purposes of energization detection (for the
energization inhibit feature of the percent differential element), overexcitation protection
(the volts-per-hertz 1 and 2 functions), and frequency protection (the underfrequency,
frequency decay, and overfrequency functions). Note that the frequency elements will use
the winding 1 phase A current input if voltage is not available.
5.4.8
•
VOLTAGE INPUT PARAMETER: Enter the winding and phase of the voltage connected
to the voltage input.
•
NOMINAL VT SECONDARY VOLTAGE: Enter the nominal secondary voltage (in volts) of
the voltage transformer.
•
VT RATIO: Enter the ratio of the voltage transformer.
Ambient Temperature
PATH: SETPOINTS Z S2 SYSTEM SETUP ZV AMBIENT TEMP
AMBIENT TEMPERATURE
SENSING: Disabled
Range:
Enabled, Disabled
MESSAGE
AMBIENT RTD TYPE:
100 Ω Platinum
Range:
100 Ω Platinum, 120 Ω Nickel,
100 Ω Nickel, By Monthly
Average
MESSAGE
AVERAGE AMBIENT TEMP
FOR JANUARY: 20°C
Range:
–50 to 125°C in steps of 1
Range:
–50 to 125°C in steps of 1
„ AMBIENT TEMP [Z]
↓
MESSAGE
•
AVERAGE AMBIENT TEMP
FOR DECEMBER: 20°C
AMBIENT RTD SENSING: Select “Enabled” to use an RTD to monitor ambient
temperature.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–39
SETPOINTSCHAPTER 5: SETPOINTS
•
AMBIENT RTD TYPE: The 745 provides an RTD input for monitoring the ambient
temperature. The three RTD types which may be used are 100 Ω platinum, and 100/
120 Ω nickel, the characteristics of which are as follows:
Table 5–3: RTD resistance vs. temperature
•
5–40
Temperature
100 Ω Platinum
120 Ω Nickel
100 Ω Nickel
–50°C
80.31 Ω
86.17 Ω
71.81 Ω
–40°C
84.27 Ω
92.76 Ω
79.13 Ω
–30°C
88.22 Ω
99.41 Ω
84.15 Ω
89.23 Ω
–20°C
92.16 Ω
106.15 Ω
–10°C
96.09 Ω
113.00 Ω
94.58 Ω
0°C
100.00 Ω
120.00 Ω
100.00 Ω
10°C
103.90 Ω
127.17 Ω
105.60 Ω
20°C
107.79 Ω
134.52 Ω
111.20 Ω
30°C
111.67 Ω
142.06 Ω
117.10 Ω
40°C
115.54 Ω
149.79 Ω
123.01 Ω
50°C
119.39 Ω
157.74 Ω
129.11 Ω
60°C
123.24 Ω
165.90 Ω
135.34 Ω
70°C
127.07 Ω
174.25 Ω
141.72 Ω
80°C
130.89 Ω
182.84 Ω
148.25 Ω
90°C
134.70 Ω
191.64 Ω
154.90 Ω
100°C
138.50 Ω
200.64 Ω
161.78 Ω
110°C
142.29 Ω
209.85 Ω
168.79 Ω
120°C
146.06 Ω
219.29 Ω
175.98 Ω
130°C
149.82 Ω
228.96 Ω
183.35 Ω
140°C
153.58 Ω
238.85 Ω
190.90 Ω
150°C
157.32 Ω
248.95 Ω
198.66 Ω
160°C
161.04 Ω
259.30 Ω
206.62 Ω
170°C
164.76 Ω
269.91 Ω
214.81 Ω
223.22 Ω
180°C
168.47 Ω
280.77 Ω
190°C
172.46 Ω
291.96 Ω
243.30 Ω
200°C
175.84 Ω
303.46 Ω
252.88 Ω
210°C
179.51 Ω
315.31 Ω
262.76 Ω
220°C
183.17 Ω
327.54 Ω
272.94 Ω
230°C
186.82 Ω
340.14 Ω
283.94 Ω
240°C
190.45 Ω
353.14 Ω
294.28 Ω
250°C
194.08 Ω
366.53 Ω
305.44 Ω
AVERAGE AMBIENT TEMPERATURE (BY MONTH): This message is displayed only when
the AMBIENT RTD TYPE is set for “By Monthly Average”. Ambient temperature is used in
the calculation of Insulation Aging and must be enabled for the function to operate.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
5.4.9
Analog Input
PATH: SETPOINTS ZV S2 SYSTEM SETUP ZV ANALOG INPUT
ANALOG INPUT NAME:
Analog Input
Range:
18 alphanumeric characters
MESSAGE
ANALOG INPUT UNITS:
μA
Range:
6 alphanumeric characters
MESSAGE
ANALOG INPUT RANGE:
0-1 mA
Range:
0-1 mA, 0-5 mA, 4-20 mA, 0-20
mA.
MESSAGE
ANALOG INPUT MINIMUM
VALUE: 0 μA
Range:
0 to 65000 in steps of 1
MESSAGE
ANALOG INPUT MAXIMUM
VALUE: 1000 μA
Range:
0 to 65000 in steps of 1
„ ANALOG INPUT [Z]
The 745 provides a general purpose DC current input for use in monitoring any external
parameter. Any standard transducer output may be connected to the analog input for
monitoring.
•
ANALOG INPUT NAME: Press ENTER to begin editing the name of the analog input.
The text may be changed from “Analog Input” one character at a time, using the
VALUE keys. Press the ENTER key to store the edit and advance to the next character
position. This name will appear in the actual value message A2 METERING ZV
ANALOG INPUT.
•
ANALOG INPUT UNITS: Enter the units of the quantity being read by editing the text as
described above. The six characters entered will be displayed instead of “Units”
wherever the analog input units are displayed.
•
ANALOG INPUT RANGE: Select the current output range of the transducer that is
connected to the analog input. The units are defined by the ANALOG INPUT UNITS
setpoint.
•
ANALOG INPUT MINIMUM/MAXIMUM: Enter the value of the quantity measured
which corresponds to the minimum/maximum output value of the transducer. The
units are defined by the ANALOG INPUT UNITS setpoint.
5.4.10 Demand Metering
PATH: SETPOINTS ZV S2 SYSTEM SETUP ZV DEMAND METERING
CURRENT DEMAND METER
TYPE: Thermal
Range:
Thermal, Block Interval, Rolling
Demand
MESSAGE
THERMAL 90% RESPONSE
TIME: 15 min.
Range:
5, 10, 15, 20, 25, 30, 60 min.
MESSAGE
TIME INTERVAL:
20 min.
Range:
5, 10, 15, 20, 25, 30, 60 min.
(see note below)
„ DEMAND METERING [Z]
This section assigns the demand setpoints for monitoring current demand on all three
phases of each windings. Current demand on the 745 is performed one of three ways:
thermal, rolling demand, or block interval.
•
CURRENT DEMAND METER TYPE: Select the method to be used for the current
demand metering.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–41
SETPOINTSCHAPTER 5: SETPOINTS
Select “Thermal” to emulate the action of an analog peak-recording thermal demand
meter. The 745 measures the current on each phase every second, and assumes the circuit
quantity remains at this value until updated by the next measurement. It calculates the
‘thermal demand equivalent’ as follows:
d(t) = D(1 – e
where
– kt
)
(EQ 5.3)
d = demand after applying input for time t (in minutes)
D = input quantity (constant)
2.3
k = -------------------------------------------------------------------------
Thermal 90% Response Time
Demand (%)
100
80
60
40
20
0
0
3
6
9
12
15
18
21
24
27
30
Time (min)
FIGURE 5–6: Thermal demand time
Select “Block Interval” to calculate a linear average of the current over the programmed
demand TIME INTERVAL, starting daily at 00:00:00 (that is, 12 am). The 1440 minutes per
day is divided into the number of blocks as set by the programmed time interval. Each new
value of demand becomes available at the end of each time interval.
Select “Rolling Demand” to calculate a linear average of the current over the programmed
demand TIME INTERVAL (in the same way as Block Interval above). The value is updated
every minute and indicates the demand over the time interval just preceding the time of
update.
Note
5–42
•
THERMAL 90% RESPONSE TIME: This message is displayed only when the CURRENT
DEMAND METER TYPE is set for “Thermal”. Enter the time required for a steady-state
current to indicate 90% of actual value.
•
TIME INTERVAL: This message is displayed only when the CURRENT DEMAND METER
TYPE is set for “Block Interval” or “Rolling Demand”. Enter the time period over which
the current demand calculation is performed.
The TIME INTERVAL is only displayed when “Block Interval” or “Rolling Demand” is selected
for the CURRENT DEMAND METER TYPE.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
5.4.11 Analog Outputs 1 to 7
PATH: SETPOINTS ZV S2 SYSTEM SETUP ZV ANALOG OUTPUTS Z ANALOG OUTPUT 1(7)
ANALOG OUTPUT 1
FUNCTION: Disabled
Range:
Enabled, Disabled
MESSAGE
ANALOG OUTPUT 1
VALUE: W1 ΦA Current
Range:
see table below
MESSAGE
ANALOG OUTPUT 1
RANGE: 4-20 mA
Range:
0-1 mA, 0-5 mA, 4-20 mA, 0-20
mA, 0-10 mA
MESSAGE
ANALOG OUTPUT 1
MIN: 0 A
Range:
matches the range of the
selected measured parameter
MESSAGE
ANALOG OUTPUT 1
MAX: 1000 A
Range:
matches the range of the
associated actual value
„ ANALOG OUTPUT 1 [Z]
There are seven analog outputs on the 745 relay which are selected to provide a full-scale
output range of one of 0 to 1 mA, 0 to 5 mA, 4 to 20 mA, 0 to 20 mA or 0 to 10 mA. Each
channel can be programmed to monitor any measured parameter. This sub-section is only
displayed with the option installed.
•
ANALOG OUTPUT 1(7) FUNCTION: This message enables or disables the analog
output 1(7) feature. When disabled, 0 mA will appear at the corresponding terminal.
•
ANALOG OUTPUT 1(7) VALUE: Select the measured parameter below to be
represented by the mA DC current level of analog output 1(7).
Parameter
Description
W1(3) ΦA Current
W1(3) ΦB Current
W1(3) ΦC Current
Select to monitor the RMS value (at fundamental frequency) of the
winding 1(3) Phase A, B, and C current inputs.
W1(3) Loading
Select to monitor the winding 1(3) load as a percentage of the rated
load for that winding.
W1(3) ΦA THD
W1(3) ΦB THD
W1(3) ΦC THD
Select to monitor the total harmonic distortion in the winding 1(3)
phase A, B, and C current inputs.
W1(3) Derating
Select to monitor the harmonic derating factor (that is, the derated
transformer capability while supplying non-sinusoidal load currents)
in winding 1(3).
Frequency
Select to monitor the system frequency.
Tap Position
Select to monitor the onload tap changer position.
Voltage
Select to monitor the system voltage as measured from the voltage
input.
W1(3) ΦA Demand
W1(3) ΦB Demand
W1(3) ΦC Demand
Select to monitor the current demand value of the winding 1(3)
phase A, B, and C current inputs.
Analog Input
Select to monitor the general purpose analog input current.
MaxEvnt W1(3) Ia
MaxEvnt W1(3) Ib
MaxEvnt W1(3) Ic
MaxEvnt W1(3) Ia
Select to monitor the maximum captured RMS value (at fundamental
frequency) of the winding 1(3) phase A, B, C, and ground current
input for all events since the last time the event recorder was
cleared.
•
ANALOG OUPUT 1(7) RANGE: Select the full-scale range of output current for analog
output 1(7).
•
ANALOG OUTPUT 1(7) MIN/MAX: Enter the value of the selected parameter which
corresponds to the minimum/maximum output current of analog output 1(7).
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–43
SETPOINTSCHAPTER 5: SETPOINTS
5.5
S3 Logic Inputs
5.5.1
Description
The are two types of digital inputs: Logic inputs have physical terminals for connecting to
external contacts; Virtual inputs provide the same function as logic inputs, but have no
physical external connections. A setpoint defines the state of each in virtual input in terms
of “On” or “Off”.
There are sixteen each of logic and virtual inputs. The state (‘asserted’ or ‘not asserted’) of
each logic or virtual input can be used to activate a variety of predefined logic functions,
such as protection element blocking, energization detection, etc. In addition, any logic or
virtual input can be used as an input in FlexLogic™ equations to implement custom
schemes.
5.5.2
Logic Inputs 1 to 16
PATH: SETPOINTS ZV S3 LOGIC INPUTS Z LOGIC INPUTS Z LOGIC INPUT 1(16)
INPUT 1 FUNCTION:
Disabled
Range:
Enabled, Disabled
MESSAGE
INPUT 1 TARGET:
Self-Reset
Range:
None, Latched, Self-Reset
MESSAGE
INPUT 1 NAME:
Logic Input 1
Range:
18 alphanumeric characters
MESSAGE
INPUT 1 ASSERTED
STATE: Closed
Range:
Open, Closed
„ LOGIC INPUT 1 [Z]
5–44
•
INPUT 1(16) FUNCTION: Select “Enabled” if this logic input is to be used. Selecting
“Disabled” prevents this logic input from achieving the asserted (or signaling) state.
•
INPUT 1(16) TARGET: Selecting “None” inhibits target message display when the input
is asserted. Thus, an input with target type “None” never disables the LED self-test
feature since it cannot generate a displayable target message.
•
INPUT 1(16) NAME: Press ENTER to edit the login input name. The text may be
changed from “Logic Input 1” one character at a time with the VALUE keys. Press
ENTER to store and advance to the next character position.
•
INPUT 1(16) ASSERTED STATE: Select “Closed” as when connected to a normally open
contact (where the signaling state is closed). Select “Open” when connected to a
normally closed contact (where the signaling state is open).
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
5.5.3
Virtual Inputs 1 to 16
PATH: SETPOINTS ZV S3 LOGIC INPUTS ZV VIRTUAL INPUTS Z VIRTUAL INPUTS 1(16)
„ VIRTUAL
INPUT 1 FUNCTION:
Disabled
Range:
Enabled, Disabled
MESSAGE
INPUT 1 TARGET:
Self-Reset
Range:
None, Latched, Self-Reset
MESSAGE
INPUT 1 NAME:
Virtual Input 1
Range:
18 alphanumeric characters
MESSAGE
INPUT 1 PROGRAMMED
STATE: Not Asserted
Range:
Not Asserted, Asserted
[Z]
INPUT 1
•
INPUT 1(16) FUNCTION: Select “Enabled” if this virtual input is to be used. Selecting
“Disabled” prevents this virtual input from achieving the asserted (or signaling) state.
•
INPUT 1(16) TARGET: Selecting “None” inhibits target message display when the input
is asserted. Thus, an input whose target type is “None” never disables the LED self-test
feature since it cannot generate a displayable target message.
•
INPUT 1(16) NAME: Press ENTER to edit the login input name. The text may be
changed from “Virtual Input 1” one character at a time with the VALUE keys. Press
ENTER to store and advance to the next character position.
•
INPUT 1(16) PROGRAMMED STATE: Select “Asserted” to place the virtual input into the
signaling state; likewise, select “Not Asserted” to place it into the non-signaling state.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–45
SETPOINTSCHAPTER 5: SETPOINTS
5.6
S4 Elements
5.6.1
Introduction to Elements
Protection and monitoring elements are configured in this page. This includes complete
differential protection; phase, neutral, ground, negative sequence overcurrent; restricted
ground fault (differential ground); under, over, and rate-of-change of frequency;
overexcitation; harmonic monitoring; analog input monitoring; current demand
monitoring; and transformer overload monitoring.
Each element is comprised of a number of setpoints, some of which are common to all
elements. These common setpoints are described below, avoiding repeated descriptions
throughout this section:
<NAME OF ELEMENT>
FUNCTION: Enabled
Range: Disabled, Enabled
<NAME OF ELEMENT>
RLYS (1-8):
Range: 1 TO 8
<NAME OF ELEMENT>
TARGET: Latched
Range: Self-reset, Latched, None
<NAME OF ELEMENT>
BLOCK: Disabled
Range: Disabled, Logc Inpt 1 to 16, Virt Inpt 1 to 16, Output
Rly 1 to 8, SelfTest Rly, Virt Outpt 1 to 5
Select “Enabled” to enable the element. For critical protection
elements, this setpoint is normally “Enabled” except for test
purposes. For elements which are not to be used, this
setpoint should be set to “Disabled”.
Select output relay to be configured for the element.
Target messages indicate which elements have picked up or
operated. Select “Latched” to keep the element target
message in the queue of target messages, even after the
condition which caused the element to operate has been
cleared, until a reset command is issued. Select “Self-reset” to
automatically remove the target message from the message
queue after the condition has been cleared. Select “None” to
inhibit the display of the target message when the element
operates. An element whose target type is “None” will never
disable the LED self-test feature because can not generate a
displayable target message.
Select any logic input, virtual input, output relay, or virtual
output which, when asserted or operated, blocks the element
from operating. Selecting a logic or virtual input allows
blocking the element based on a decision external to the 745.
Selecting an output relay or virtual output allows blocking the
element based on conditions detected by the 745 and the
combination of logic programmed in the associated
FlexLogic™ equation.
Following the setpoint descriptions are logic diagrams illustrating how each setpoint, input
parameter, and internal logic is used in a feature to obtain an output. The logic diagrams
are organized into the following functional blocks:
5–46
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
SETPOINTS
•
Shown as a block with the heading SETPOINT.
•
The exact wording of the displayed setpoint message identifies the setpoint.
•
Major functional setpoint selections are listed below the name and are incorporated in
the logic.
MEASUREMENT UNITS
•
Shown as a block with inset labelled RUN.
•
The associated pickup or dropout setpoint is shown directly above.
•
Operation of the detector is controlled by logic entering the RUN inset.
•
Relationship between setpoint and input parameter is indicated by simple
mathematical symbols: <, >, etc.
TIME DELAYS
tPKP=DELAY
tDO=0
•
Shown as a block with the following schematic symbol:
.
•
The delay before pickup is indicated by tPKP, and the delay after dropout is indicated by
tDO.
•
If the delay before pickup is adjustable, the associated delay setpoint is shown directly
above, and the schematic symbol indicates that tPKP = DELAY.
LED INDICATORS
•
Shown as the following schematic symbol: ⊗.
•
The exact wording of the front panel label identifies the indicator.
LOGIC
•
5.6.2
Described using basic AND gates and OR gates
Setpoint Group
PATH: SETPOINTS ZV S4 ELEMENTS Z SETPOINT GROUP
ACTIVE SETPOINT
GROUP: Group 1
Range:
Group 1, Group 2, Group 3,
Group 4
MESSAGE
EDIT SETPOINT
GROUP: Active Group
Range:
Group 1, Group 2, Group 3,
Group 4, Active Group
MESSAGE
GROUP 2 ACTIVATE
SIGNAL: Disabled
Range:
Logic Input 1 to 16, Disabled
MESSAGE
GROUP 3 ACTIVATE
SIGNAL: Disabled
Range:
Logic Input 1 to 16, Disabled
MESSAGE
GROUP 4 ACTIVATE
SIGNAL: Disabled
Range:
Logic Input 1 to 16, Disabled
„ SETPOINT GROUP [Z]
Each protection and monitoring element setpoint (programmed in S4 ELEMENTS) has four
copies, and these settings are organized in four setpoint groups. Only one group of settings
are active in the protection scheme at a time. The active group can be selected using the
ACTIVE SETPOINT GROUP setpoint or using a logic input. The setpoints in any group can be
viewed or edited using the EDIT SETPOINT GROUP setpoint.
•
ACTIVE SETPOINT GROUP: Select the number of the SETPOINT GROUP whose settings
are to be active in the protection scheme. This selection will be overridden if a higher
number setpoint group is activated using logic inputs.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–47
SETPOINTSCHAPTER 5: SETPOINTS
5.6.3
•
EDIT SETPOINT GROUP: Select the number of the SETPOINT GROUP whose settings
are to be viewed and/or edited via the front panel keypad or any of the
communication ports. Selecting “Active Group” selects the currently active setpoint
group for editing.
•
GROUP 2(4) ACTIVATE SIGNAL: Select any logic input which, when asserted, will
(remotely) select SETPOINT GROUP 2(4) to be the active group. This selection will be
overridden if a higher number setpoint group is activated using the ACTIVE SETPOINT
GROUP setpoint or another logic input.
Differential Element
5.6.3.1 Main menu
PATH: SETPOINTS ZV S4 ELEMENTS ZV DIFFERENTIAL
„ DIFFERENTIAL [Z]
[ Z]
DIFFERENTIAL
„ PERCENT
MESSAGE
MESSAGE
MESSAGE
„ HARMONIC
[Z]
INHIBIT
„ ENERGIZATION [Z]
INHIBIT
„ 5th HARM
INHIBIT
[ Z]
See page 5–49
See page 5–52
See page 5–53
See page 5–56
This section contains the settings to configure the percent differential element, including
all associated harmonic inhibit features. The 745 provides three independent harmonic
inhibit features: HARMONIC INHIBIT, which implements an inhibit scheme based on 2nd or
2nd + 5th harmonic which is ‘in-circuit’ at all times; ENERGIZATION INHIBIT, which allows
changing the characteristics of the inhibit scheme during energization to improve
reliability; and 5TH HARM INHIBIT, which implements an inhibit scheme based on 5th
harmonic only, allowing inhibiting the percent differential during intentional overexcitation
of the system.
5–48
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
5.6.3.2 Percent Differential
PATH: SETPOINTS ZV S4 ELEMENTS ZV DIFFERENTIAL Z PERCENT DIFFERENTIAL
PERCENT DIFFERENTIAL
FUNCTION: Enabled
Range:
Enabled, Disabled
MESSAGE
PERCENT DIFFERENTIAL
RLYS (1-8): --------
Range:
1 to 8
MESSAGE
PERCENT DIFFERENTIAL
TARGET: Latched
Range:
Self-Reset, Latched, None
MESSAGE
PERCENT DIFFERENTIAL
PICKUP: 0.30 x CT
Range:
0.05 to 1.00 x CT in steps of
0.01
MESSAGE
PERCENT DIFFERENTIAL
SLOPE 1: 25%
Range:
15 to 100% in steps of 1
MESSAGE
PERCENT DIFFERENTIAL
KNEEPOINT: 2.0 x CT
Range:
1.0 to 20.0 x CT in steps of 0.1
MESSAGE
PERCENT DIFFERENTIAL
SLOPE 2: 100%
Range:
50 to 100% in steps of 1
MESSAGE
PERCENT DIFFERENTIAL
BLOCK: Disabled
Range:
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
[ Z]
DIFFERENTIAL
„ PERCENT
This section contains the settings to configure the percent differential element. The main
purpose of the percent-slope characteristic of the differential element is to prevent
maloperation because of unbalances between CTs during external faults. These
unbalances arise as a result of the following factors:
• CT ratio mismatch (not a factor, since the 745 automatically corrects for this
mismatch)
• Onload tap changers which result in dynamically changing CT mismatch
• CT accuracy errors
• CT saturation
The basic operating principle of the percent differential element can be described by the
following diagram and its associated equations:
V1
V3
CT3
CT1
CT2
V2
I1
I2
I3
Percent
Diff
Element
FIGURE 5–7: Percent differential operating principle
Note
Restraint current calculations have been changed from average to maximum to
provide better security during external faults.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–49
SETPOINTSCHAPTER 5: SETPOINTS
The basic percent differential operating principle for three-winding transformers is
illustrated by the following equations:
I r = I restraint = max ( I 1 , I 2 , I 3 ) ; I d = I differential = I 1 + I 2 + I 3
(EQ 5.4)
Id
%slope = ---- × 100%
Ir
The basic percent differential operating principle for two-winding transformers is
illustrated by the following equations:
I r = I restraint = max ( I 1 , I 2 ) ; I d = I differential = I 1 + I 2
(EQ 5.5)
Id
%slope = ---- × 100%
Ir
where
Note
Irestraint = per-phase maximum of the currents after phase, ratio, and zerosequence correction;
Idifferential = per-phase vector sum of currents after phase, ratio, and zerosequence correction
In the above equations, the 180° phase shift due to the wiring connections is taken into
account, hence the + sign to obtain the differential current.
200%
Idifferential (x CT)
SLOPE 2
100%
OPERATE
REGION
100%
1.00
PICKUP 0.30
0.05
50%
SLOPE 1
25%
15%
2.0
KNEEPOINT
RESTRAINT
REGION
Irestraint (x CT)
FIGURE 5–8: Percent differential dual-slope characteristic
The base for the percent differential setpoints is the S2 SYSTEM SETUP ZV WINDING 1 ZV
WINDING 1 PHASE CT PRIMARY setpoint value. The percent differential setpoints are
explained below.
5–50
•
PERCENT DIFFERENTIAL PICKUP: Enter the minimum differential current required for
operation. This setting is chosen based on the amount of differential current that
might be seen under normal operating conditions.
•
PERCENT DIFFERENTIAL SLOPE 1: Enter the slope 1 percentage (of differential current
to restraint current) for the dual-slope percent differential element. The slope 1 setting
is applicable for restraint currents of zero to the kneepoint, and defines the ratio of
differential to restraint current above which the element will operate. This slope is set
to ensure sensitivity to internal faults at normal operating current levels. The criteria
for setting this slope are:
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
Note
–
To allow for mismatch when operating at the limit of the transformer’s onload
tap-changer range.
–
To accommodate for CT errors.
•
PERCENT DIFFERENTIAL KNEEPOINT: Enter the kneepoint for the dual-slope percent
differential element. This is the transition point between slopes 1 and 2, in terms of
restraint current, in units of relay nominal current. Set the kneepoint just above the
maximum operating current level of the transformer between the maximum forcedcooled rated current and the maximum emergency overload current level.
•
PERCENT DIFFERENTIAL SLOPE 2: Enter the slope 2 percentage (of differential current
to restraint current) for the dual-slope percent differential element. This setting is
applicable for restraint currents above the kneepoint and is set to ensure stability
under heavy through fault conditions which could lead to high differential currents as
a result of CT saturation.
Since I restraint' = max ( I 1 , I 2 , I 3 ) , the differential current is not always greater than 100%
of the restraint current. Because of this enhancement, the PERCENT DIFFERENTIAL SLOPE 2
setting may cause slow operation (in rare cases no operation) in the following situations:
1.
PERCENT DIFFERENTIAL SLOPE 2 is set above 100%.
2.
The source is connected to one winding only.
Therefore, the PERCENT DIFFERENTIAL SLOPE 2 value cannot be greater than 100%. To
increase dependability, the Slope 2 settings should be less than 98%
FIGURE 5–9: Percent differential scheme logic
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–51
SETPOINTSCHAPTER 5: SETPOINTS
5.6.3.3 Harmonic inhibit
PATH: SETPOINTS ZV S4 ELEMENTS ZV DIFFERENTIAL ZV HARMONIC INHIBIT
„ HARMONIC
HARMONIC INHIBIT
FUNCTION: Enabled
Range:
Enabled, Disabled
MESSAGE
HARMONIC INHIBIT
PARAMETERS: 2nd
Range:
2nd, 2nd + 5th
MESSAGE
HARMONIC AVERAGING:
Disabled
Range:
Enabled, Disabled
MESSAGE
HARMONIC INHIBIT
LEVEL: 20.0% f0
Range:
0.1 to 65.0% f0 in steps of 0.1
[Z]
INHIBIT
This menu contains the percent differential harmonic inhibit settings. This is the percent
differential element in a particular phase if the 2nd harmonic of the same phase exceeds
the HARMONIC INHIBIT LEVEL setpoint. With harmonic inhibit parameters set to
“2nd + 5th”, the RMS sum of the 2nd and 5th harmonic components is compared against
the level setting. With harmonic averaging enabled, all three phases are inhibited if the 3phase average of the harmonics exceeds the level setting
•
HARMONIC INHIBIT PARAMETERS: Select “2nd” to compare only the 2nd harmonic
current against the HARMONIC INHIBIT LEVEL . Select “2nd + 5th” to use the RMS sum
of the 2nd and 5th harmonic components. For most transformers, the 2nd harmonic
current alone will exceed 20% during energization and the “2nd” value is sufficient to
inhibit the differential element for inrush current.
•
HARMONIC AVERAGING: Select “Enabled” to use the three-phase average of the
harmonic current against the harmonic inhibit setting. For most applications, enabling
harmonic averaging is not recommended.
•
HARMONIC INHIBIT LEVEL: Enter the level of harmonic current (2nd or 2nd+5th) above
which the percent differential element will be inhibited from operating. For most
applications, this level should be set to “20%”.
FIGURE 5–10: Harmonic inhibit scheme logic
5–52
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
5.6.3.4 Energization inhibit
PATH: SETPOINTS ZV S4 ELEMENTS ZV DIFFERENTIAL ZV ENERGIZATION INHIBIT
ENERGIZATION INHIBIT
FUNCTION: Enabled
Range:
Enabled, Disabled
MESSAGE
ENERGIZATION INHIBIT
PARAMETERS: 2nd
Range:
2nd, 2nd + 5th
MESSAGE
HARMONIC AVERAGING:
Enabled
Range:
Enabled, Disabled
MESSAGE
ENERGIZATION INHIBIT
LEVEL: 20.0% f0
Range:
0.1 to 65.0% f0 in steps of 0.1
MESSAGE
ENERGIZATION INHIBIT
DURATION: 0.10 s
Range:
0.05 to 600.00 s in steps of 0.01
MESSAGE
ENERGIZATION SENSING
BY CURRENT: Enabled
Range:
Enabled, Disabled
MESSAGE
MINIMUM ENERGIZATION
CURRENT: 0.10 x CT
Range:
0.10 to 0.50 x CT in steps of
0.01
MESSAGE
ENERGIZATION SENSING
BY VOLTAGE: Disabled
Range:
Enabled, Disabled. Seen only if
Voltage Sensing is enabled.
MESSAGE
MINIMUM ENERGIZATION
VOLTAGE: 0.85 x VT
Range:
0.50 to 0.99 x VT in steps of
0.01. Seen only if Voltage
Sensing is enabled.
MESSAGE
BREAKERS ARE OPEN
SIGNAL: Disabled
Range:
Logic Input 1 to 16, Disabled
MESSAGE
PARALL XFMR BRKR CLS
SIGNAL: Disabled
Range:
Logic Input 1 to 16, Disabled
„ ENERGIZATION [Z]
INHIBIT
Over and above the standard harmonic inhibit feature programmed above, the 745
contains a harmonic inhibit feature which is in service only during energization and/or
sympathetic inrush. De-energization and energization of the transformer is detected by
any of the following three methods:
1.
With energization sensing by current enabled, all currents dropping below the
minimum energization current indicates de-energization; any current exceeding the
minimum energization current indicates energization. This method is the least reliable
method of detecting energization, since an energized and unloaded transformer will
be detected as being de-energized if this method is used alone.
2.
With energization sensing by voltage enabled, the voltage dropping below the
minimum energization voltage indicates de-energization; any current exceeding the
minimum energization current indicates energization.
3.
With ‘b’ auxiliary contacts from all switching devices (which can be used to energize
the transformer) connected in series to a logic input and assigned to the BREAKERS
ARE OPEN setpoint, the contacts closed indicates de-energization; any current
exceeding the minimum energization current indicates energization.
Energization inhibit settings are put in service upon detection of de-energization. Upon
energization, the energization inhibit duration timer is initiated and the settings are
removed from service when the time delay elapses. The energization inhibit feature may
also be put in service during sympathetic inrush. The onset of sympathetic inrush is
detected via a close command to the parallel transformer switching device connected to a
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–53
SETPOINTSCHAPTER 5: SETPOINTS
logic input, assigned to the PARALL XFMR BRKR CLS setpoint. Energization inhibit settings
are put in service when the contact closes. Upon signal removal, the energization inhibit
duration timer is initiated and the settings are removed from service when the time delay
elapses.
In a breaker-and-a-half scheme, where current can be present in the CTs without being
present in the transformer winding, it may be necessary to use the parallel transformer
breaker close contact to initiate energization inhibit.
5–54
•
ENERGIZATION INHIBIT PARAMETERS: Select “2nd” to compare the 2nd harmonic
current against HARMONIC INHIBIT LEVEL . Select “2nd + 5th” to use the RMS sum of
the 2nd and 5th harmonics.
•
HARMONIC AVERAGING: Select “Enabled” to use the three-phase average of the
harmonic current against the harmonic inhibit setting.
•
ENERGIZATION INHIBIT LEVEL: Enter the level of harmonic current (2nd or 2nd + 5th)
above which the percent differential element is inhibited from operating. This setting
will often need to be set significantly lower than the HARMONIC INHIBIT LEVEL ,
especially when used with the “Parallel Xfmr BkrCls” logic input function for
sympathetic inrush.
•
ENERGIZATION INHIBIT DURATION: Enter the time delay from the moment of
energization (or the end of the parallel breaker close command) before the
energization inhibit feature is removed from service.
•
ENERGIZATION SENSING BY CURRENT: Select “Enabled” to detect de-energization by
the level of all currents dropping below the minimum energization current.
•
MINIMUM ENERGIZATION CURRENT: Enter the current level below which the
transformer is considered de-energized (energization sensing by current enabled), and
above which the transformer is considered energized (any energization sensing
enabled).
•
ENERGIZATION SENSING BY VOLTAGE: Select “Enabled” to detect de-energization by
the level of the voltage dropping below the minimum energization voltage. This
setpoint is displayed only if S2 SYSTEM SETUP ZV VOLTAGE INPUT Z VOLTAGE SENSING
is “Enabled”.
•
MINIMUM ENERGIZATION VOLTAGE: Enter the voltage level below which the
transformer is considered de-energized (when ENERGIZATION SENSING BY VOLTAGE is
“Enabled”). This setpoint is displayed only if S2 SYSTEM SETUP ZV VOLTAGE INPUT Z
VOLTAGE SENSING is “Enabled”.
•
BREAKERS ARE OPEN SIGNAL: Select any logic input which, when asserted, indicates
to the 745 that the transformer is de-energized. The selected logic input should be
connected to the auxiliary contacts of the transformer breaker or disconnect switch.
•
PARALL XFMR BRKR CLS SIGNAL: Select any logic input which, when asserted, will
indicate to the 745 the onset of sympathetic inrush. The selected logic input should be
connected to the close command going to the parallel transformer switching device.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
FIGURE 5–11: Energization inhibit scheme logic
FIGURE 5–12: Energization sensing scheme logic
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–55
SETPOINTSCHAPTER 5: SETPOINTS
5.6.3.5 Fifth harmonic inhibit
PATH: SETPOINTS ZV S4 ELEMENTS ZV DIFFERENTIAL ZV 5th HARM INHIBIT
„ 5th HARM
5th HARMONIC INHIBIT
FUNCTION: Enabled
Range:
Enabled, Disabled
MESSAGE
HARMONIC AVERAGING:
Disabled
Range:
0.10 to 0.50 x CT in steps of
0.01
MESSAGE
5th HARMONIC INHIBIT
LEVEL: 10.0% fo
Range:
0.1 to 65.0% f0 in steps of 0.1
[Z]
INHIBIT
The 5th harmonic inhibit feature of the percent differential element allows inhibiting the
percent differential during intentional overexcitation of the system. This feature inhibits the
percent differential element in a particular phase if the 5th harmonic of the same phase
exceeds the harmonic inhibit level setting. With harmonic averaging enabled, all three
phases are inhibited if the three-phase average of the 5th harmonic exceeds the level
setting.
•
HARMONIC AVERAGING: Select “Enabled” to use the three-phase average of the 5th
harmonic current against the harmonic inhibit setting.
•
5th HARMONIC INHIBIT LEVEL: Enter the level of 5th harmonic current above which
the percent differential element will be inhibited from operating.
FIGURE 5–13: 5th harmonic inhibit scheme logic
5–56
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
5.6.4
Instantaneous Differential
PATH: SETPOINTS ZV S4 ELEMENTS ZV INST DIFFERENTIAL
INST DIFFERENTIAL
FUNCTION: Enabled
Range:
Enabled, Disabled
MESSAGE
INST DIFFERENTIAL
RLYS (1-8): --------
Range:
1 to 8
MESSAGE
INST DIFFERENTIAL
TARGET: Latched
Range:
Self-Reset, Latched, None
MESSAGE
INST DIFFERENTIAL
PICKUP: 8.00 x CT
Range:
3.00 to 20.00 × CT in steps of
0.01
MESSAGE
INST DIFFERENTIAL
BLOCK: Disabled
Range:
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
„ INST
[Z]
DIFFERENTIAL
This section contains the settings to configure the (unrestrained) instantaneous differential
element, for protection under high magnitude internal faults.
•
INST DIFFERENTIAL PICKUP: Enter the level of differential current (in units of relay
nominal current) above which the instantaneous differential element will pickup and
operate.
FIGURE 5–14: Instantaneous differential scheme logic
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–57
SETPOINTSCHAPTER 5: SETPOINTS
5.6.5
Phase Overcurrent
5.6.5.1 Main menu
PATH: SETPOINTS ZV S4 ELEMENTS ZV PHASE OC
„ PHASE OC
[ Z]
„ W1 PHASE
[ Z]
TIME OC
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
„ W2 PHASE
[ Z]
TIME OC
„ W3 PHASE
[ Z]
TIME OC
„ W1 PHASE
[ Z]
INST OC 1
„ W2 PHASE
[ Z]
INST OC 1
„ W3 PHASE
[ Z]
INST OC 1
„ W1 PHASE
[ Z]
INST OC 2
„ W2 PHASE
[ Z]
INST OC 2
„ W3 PHASE
[ Z]
INST OC 2
See page 5–63
See page 5–63
See page 5–63
See page 5–65
See page 5–65
See page 5–65
See page 5–65
See page 5–65
See page 5–65
This section contains settings to configure the phase overcurrent elements. Included are
phase time overcurrents and two levels of phase instantaneous overcurrent for each
phase of each winding.
5.6.5.2 Time Overcurrent Curves
The inverse time overcurrent curves used by the time overcurrent elements are the ANSI,
IEC, and GE type IAC curve shapes. This allows for simplified coordination with downstream
devices. If however, none of these curve shapes is adequate, FlexCurves™ may be used to
customize the inverse time curve characteristics. The Definite Time curve is also an option
that may be appropriate if only simple protection is required.
The following overcurrent curve types are available:
•
ANSI curves: ANSI extremely inverse, ANSI very inverse, ANSI normally inverse, and
ANSI moderately inverse
•
IEC curves: IEC curves A, B, and C (BS142); IEC short inverse
•
GE type IAC curves: IAC extremely inverse, IAC very inverse, IAC inverse, and IAC short
inverse
•
Other curves: FlexCurves™ A, B, and C; definite time curve
A time dial multiplier setting allows selection of a multiple of the base curve shape (where
the time dial multiplier = 1) with the curve shape (SHAPE) setting. Unlike the
electromechanical time dial equivalent, operate times are directly proportional to the time
multiplier (TIME OC MULTIPLIER) setting value. For example, all times for a multiplier of 10
are 10 times the multiplier 1 or base curve values. Setting the multiplier to zero results in an
instantaneous response to all current levels above pickup.
5–58
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
Note
Graphs of standard time-current curves on 11” × 17” log-log graph paper are available
upon request from the GE Multilin literature department. The original files are also
available in PDF from the GE Multilin website at http://www.GEmultilin.com.
FlexCurves™:
The custom FlexCurve™ is described in FlexCurves™ on page 5–38. The curve shapes for
the FlexCurves™ are derived from the formula:
I
T = M × FlexcurveTime at --------------I pickup
I
when --------------- ≥ 1.00
I pickup
(EQ 5.6)
where: T = operate time (in seconds)
M = multiplier setting,
I = input current, and
Ipickup = pickup current setpoint
Definite time curve:
The definite time curve shape operates as soon as the pickup level is exceeded for a
specified period of time. The base definite time curve delay is 0.1 seconds. The curve
multiplier makes this delay adjustable from 0.000 (instantaneous) to 10.000 seconds.
ANSI curves:
The ANSI TOC shapes conform to industry standards and the ANSI C37.90 curve
classifications for extremely, very, normally, and moderately inverse shapes. The ANSI
curves are derived from the formula below, where 1.03 ≤ I / Ipickup < 20.0:
D
B
E
- + ------------------------------------T = M × A + ----------------------------- + ------------------------------------2
3
I ⁄ Ipickup – C ( I ⁄ I pickup – C )
( I ⁄ I pickup – C )
(EQ 5.7)
where: T = operate time (in seconds), M = multiplier setpoint, I = input current
Ipickup = pickup current setpoint, and A, B, C, D, E = constants
Table 5–4: ANSI curve constants
A
B
C
D
E
ANSI extremely inverse
ANSI curve shape
0.0399
0.2294
0.5000
3.0094
0.7222
ANSI very inverse
0.0615
0.7989
0.3400
–0.2840
4.0505
ANSI normally inverse
0.0274
2.2614
0.3000
–4.1899
9.1272
ANSI moderately inverse
0.1735
0.6791
0.8000
–0.0800
0.1271
Table 5–5: ANSI curve trip times (in seconds)
TDM
Current ( I / Ipickup)
1.5
2.0
3.0
0.5
1.0
2.0
4.0
6.0
8.0
10.0
2.000
0.872
4.001
1.744
8.002
3.489
16.004 6.977
24.005 10.466
32.007 13.955
40.009 17.443
0.330
0.659
1.319
2.638
3.956
5.275
6.594
0.5
1.0
2.0
1.567
3.134
6.268
0.268
0.537
1.074
0.663
1.325
2.650
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
4.0
5.0
6.0
ANSI Extremely Inverse
0.184
0.124
0.093
0.368
0.247
0.185
0.736
0.495
0.371
1.472
0.990
0.742
2.208
1.484
1.113
2.944
1.979
1.483
3.680
2.474
1.854
ANSI Very Inverse
0.171
0.130
0.108
0.341
0.260
0.216
0.682
0.520
0.432
7.0
8.0
9.0
10.0
0.075
0.149
0.298
0.596
0.894
1.192
1.491
0.063
0.126
0.251
0.503
0.754
1.006
1.257
0.055
0.110
0.219
0.439
0.658
0.878
1.097
0.049
0.098
0.196
0.393
0.589
0.786
0.982
0.094
0.189
0.378
0.085
0.170
0.340
0.078
0.156
0.312
0.073
0.146
0.291
5–59
SETPOINTSCHAPTER 5: SETPOINTS
Table 5–5: ANSI curve trip times (in seconds)
TDM
Current ( I / Ipickup)
4.0
6.0
8.0
10.0
1.5
2.0
12.537 5.301
18.805 7.951
25.073 10.602
31.341 13.252
3.0
2.148
3.221
4.295
5.369
0.5
1.0
2.0
4.0
6.0
8.0
10.0
2.142
0.883
4.284
1.766
8.568
3.531
17.137 7.062
25.705 10.594
34.274 14.125
42.842 17.656
0.377
0.754
1.508
3.016
4.524
6.031
7.539
0.5
1.0
2.0
4.0
6.0
8.0
10.0
0.675
1.351
2.702
5.404
8.106
10.807
13.509
0.239
0.478
0.955
1.910
2.866
3.821
4.776
0.379
0.757
1.515
3.030
4.544
6.059
7.574
4.0
5.0
6.0
1.365
1.040
0.864
2.047
1.559
1.297
2.730
2.079
1.729
3.412
2.599
2.161
ANSI Normally Inverse
0.256
0.203
0.172
0.513
0.407
0.344
1.025
0.814
0.689
2.051
1.627
1.378
3.076
2.441
2.067
4.102
3.254
2.756
5.127
4.068
3.445
ANSI Moderately Inverse
0.191
0.166
0.151
0.382
0.332
0.302
0.764
0.665
0.604
1.527
1.329
1.208
2.291
1.994
1.812
3.054
2.659
2.416
3.818
3.324
3.020
7.0
0.755
1.133
1.510
1.888
8.0
0.680
1.020
1.360
1.700
9.0
0.625
0.937
1.250
1.562
10.0
0.583
0.874
1.165
1.457
0.151
0.302
0.604
1.208
1.812
2.415
3.019
0.135
0.270
0.541
1.082
1.622
2.163
2.704
0.123
0.246
0.492
0.983
1.475
1.967
2.458
0.113
0.226
0.452
0.904
1.356
1.808
2.260
0.141
0.281
0.563
1.126
1.689
2.252
2.815
0.133
0.267
0.533
1.066
1.600
2.133
2.666
0.128
0.255
0.511
1.021
1.532
2.043
2.554
0.123
0.247
0.493
0.986
1.479
1.972
2.465
IEC curves:
For European applications, the relay offers the four standard curves defined in IEC 255-4
and British standard BS142. These are defined as IEC Curve A, IEC Curve B, IEC Curve C, and
Short Inverse. The formulae for these curves are:
⎛
⎞
K
T = M × ⎜ ---------------------------⎟
E
⎝ ( I ⁄ I pu ) – 1⎠
(EQ 5.8)
where: T = trip time (in seconds), M = multiplier setpoint, I = input current,
Ipickup = pickup current setpoint, and K, E = constants.
Table 5–6: IEC (BS) inverse time curve constants
K
E
IEC curve A (BS142)
IEC (BS) curve shape
0.140
0.020
IEC curve B (BS142)
13.500
1.000
IEC curve C (BS142)
80.000
2.000
IEC short inverse
0.050
0.040
Table 5–7: IEC curve trip times (in seconds)
TDM
1.5
2.0
IEC curve A
0.05
0.860
0.501
0.10
1.719
1.003
0.20
3.439
2.006
0.40
6.878
4.012
0.60
10.317 6.017
0.80
13.755 8.023
1.00
17.194 10.029
5–60
3.0
4.0
0.315
0.630
1.260
2.521
3.781
5.042
6.302
0.249
0.498
0.996
1.992
2.988
3.984
4.980
Current ( I / Ipickup)
5.0
6.0
0.214
0.428
0.856
1.712
2.568
3.424
4.280
0.192
0.384
0.767
1.535
2.302
3.070
3.837
7.0
8.0
9.0
10.0
0.176
0.353
0.706
1.411
2.117
2.822
3.528
0.165
0.330
0.659
1.319
1.978
2.637
3.297
0.156
0.312
0.623
1.247
1.870
2.493
3.116
0.149
0.297
0.594
1.188
1.782
2.376
2.971
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
Table 5–7: IEC curve trip times (in seconds)
TDM
1.5
2.0
Current ( I / Ipickup)
5.0
6.0
IEC curve B
0.225
0.169
0.135
0.450
0.338
0.270
0.900
0.675
0.540
1.800
1.350
1.080
2.700
2.025
1.620
3.600
2.700
2.160
4.500
3.375
2.700
IEC curve C
0.267
0.167
0.114
0.533
0.333
0.229
1.067
0.667
0.457
2.133
1.333
0.914
3.200
2.000
1.371
4.267
2.667
1.829
5.333
3.333
2.286
IEC short time
0.044
0.038
0.034
0.088
0.075
0.067
0.175
0.150
0.135
0.351
0.301
0.269
0.526
0.451
0.404
0.702
0.602
0.538
0.877
0.752
0.673
3.0
0.05
0.10
0.20
0.40
0.60
0.80
1.00
1.350
0.675
2.700
1.350
5.400
2.700
10.800 5.400
16.200 8.100
21.600 10.800
27.000 13.500
0.05
0.10
0.20
0.40
0.60
0.80
1.00
3.200
6.400
12.800
25.600
38.400
51.200
64.000
1.333
0.500
2.667
1.000
5.333
2.000
10.667 4.000
16.000 6.000
21.333 8.000
26.667 10.000
0.05
0.10
0.20
0.40
0.60
0.80
1.00
0.153
0.306
0.612
1.223
1.835
2.446
3.058
0.089
0.178
0.356
0.711
1.067
1.423
1.778
4.0
0.338
0.675
1.350
2.700
4.050
5.400
6.750
0.056
0.111
0.223
0.445
0.668
0.890
1.113
7.0
8.0
9.0
10.0
0.113
0.225
0.450
0.900
1.350
1.800
2.250
0.096
0.193
0.386
0.771
1.157
1.543
1.929
0.084
0.169
0.338
0.675
1.013
1.350
1.688
0.075
0.150
0.300
0.600
0.900
1.200
1.500
0.083
0.167
0.333
0.667
1.000
1.333
1.667
0.063
0.127
0.254
0.508
0.762
1.016
1.270
0.050
0.100
0.200
0.400
0.600
0.800
1.000
0.040
0.081
0.162
0.323
0.485
0.646
0.808
0.031
0.062
0.124
0.247
0.371
0.494
0.618
0.029
0.058
0.115
0.231
0.346
0.461
0.576
0.027
0.054
0.109
0.218
0.327
0.435
0.544
0.026
0.052
0.104
0.207
0.311
0.415
0.518
IAC curves:
The curves for the General Electric type IAC relay family are derived from the formulae:
⎛
⎞
D
B
E
T = M × ⎜ A + -------------------------- + ---------------------------------- + ----------------------------------⎟
2
3
⎝
( ( I ⁄ Ipu ) – C ) ⎠
( I ⁄ I ) – C ( ( I ⁄ I pu ) – C )
(EQ 5.9)
pu
where: T = trip time (in seconds), M = multiplier setpoint, I = input current,
Ipickup = pickup current setpoint, and A to E are constants.
Table 5–8: GE type IAC inverse curve constants
A
B
C
D
E
IAC extreme inverse
IAC curve shape
0.0040
0.6379
0.6200
1.7872
0.2461
IAC very inverse
0.0900
0.7955
0.1000
–1.2885
7.9586
IAC inverse
0.2078
0.8630
0.8000
–0.4180
0.1947
IAC short inverse
0.0428
0.0609
0.6200
–0.0010
0.0221
Table 5–9: IAC curve trip times
TDM
0.5
1.0
2.0
4.0
1.5
2.0
3.0
1.699
3.398
6.796
13.591
0.749
1.498
2.997
5.993
0.303
0.606
1.212
2.423
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
Current ( I / Ipickup)
4.0
5.0
6.0
IAC extremely inverse
0.178
0.123
0.093
0.356
0.246
0.186
0.711
0.491
0.372
1.422
0.983
0.744
7.0
8.0
9.0
10.0
0.074
0.149
0.298
0.595
0.062
0.124
0.248
0.495
0.053
0.106
0.212
0.424
0.046
0.093
0.185
0.370
5–61
SETPOINTSCHAPTER 5: SETPOINTS
Table 5–9: IAC curve trip times
TDM
5–62
6.0
8.0
10.0
1.5
2.0
20.387 8.990
27.183 11.987
33.979 14.983
3.0
3.635
4.846
6.058
0.5
1.0
2.0
4.0
6.0
8.0
10.0
1.451
0.656
2.901
1.312
5.802
2.624
11.605 5.248
17.407 7.872
23.209 10.497
29.012 13.121
0.269
0.537
1.075
2.150
3.225
4.299
5.374
0.5
1.0
2.0
4.0
6.0
8.0
10.0
0.578
1.155
2.310
4.621
6.931
9.242
11.552
0.375
0.749
1.499
2.997
4.496
5.995
7.494
0.266
0.532
1.064
2.128
3.192
4.256
5.320
0.5
1.0
2.0
4.0
6.0
8.0
10.0
0.072
0.143
0.286
0.573
0.859
1.145
1.431
0.047
0.095
0.190
0.379
0.569
0.759
0.948
0.035
0.070
0.140
0.279
0.419
0.559
0.699
Current ( I / Ipickup)
4.0
5.0
6.0
2.133
1.474
1.115
2.844
1.966
1.487
3.555
2.457
1.859
IAC very inverse
0.172
0.133
0.113
0.343
0.266
0.227
0.687
0.533
0.453
1.374
1.065
0.906
2.061
1.598
1.359
2.747
2.131
1.813
3.434
2.663
2.266
IAC inverse
0.221
0.196
0.180
0.443
0.392
0.360
0.885
0.784
0.719
1.770
1.569
1.439
2.656
2.353
2.158
3.541
3.138
2.878
4.426
3.922
3.597
IAC short inverse
0.031
0.028
0.027
0.061
0.057
0.054
0.123
0.114
0.108
0.245
0.228
0.217
0.368
0.341
0.325
0.490
0.455
0.434
0.613
0.569
0.542
7.0
0.893
1.191
1.488
8.0
0.743
0.991
1.239
9.0
0.636
0.848
1.060
10.0
0.556
0.741
0.926
0.101
0.202
0.405
0.810
1.215
1.620
2.025
0.093
0.186
0.372
0.745
1.117
1.490
1.862
0.087
0.174
0.349
0.698
1.046
1.395
1.744
0.083
0.165
0.331
0.662
0.992
1.323
1.654
0.168
0.337
0.674
1.348
2.022
2.695
3.369
0.160
0.320
0.640
1.280
1.921
2.561
3.201
0.154
0.307
0.614
1.229
1.843
2.457
3.072
0.148
0.297
0.594
1.188
1.781
2.375
2.969
0.026
0.052
0.105
0.210
0.314
0.419
0.524
0.026
0.051
0.102
0.204
0.307
0.409
0.511
0.025
0.050
0.100
0.200
0.301
0.401
0.501
0.025
0.049
0.099
0.197
0.296
0.394
0.493
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
5.6.5.3 Winding 1(3) Phase Time Overcurrent
PATH: SETPOINTS ZV S4 ELEMENTS ZV PHASE OC Z w1(3) PHASE TIME OC
„ W1 PHASE
W1 PHASE TIME OC
FUNCTION: Enabled
Range:
Enabled, Disabled
MESSAGE
W1 PHASE TIME OC
RLYS (1-8): --------
Range:
1 to 8
MESSAGE
W1 PHASE TIME OC
TARGET: Latched
Range:
Self-Reset, Latched, None
MESSAGE
W1 PHASE TIME OC
PICKUP: 1.20 x CT
Range:
0.05 to 20.00 x CT in steps of
0.01
MESSAGE
W1 PHASE TIME OC
SHAPE: Ext Inverse
Range:
see description below
MESSAGE
W1 PHASE TIME OC
MULTIPLIER: 1.00
Range:
0.00 to 100.00 in steps of 0.01
MESSAGE
W1 PHASE TIME OC
RESET: Linear
Range:
Instantaneous, Linear
MESSAGE
W1 PHASE TIME OC
BLOCK: Disabled
Range:
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
MESSAGE
W1 HARMONIC DERATING
CORRECTION: Disabled
Range:
Logic Input 1 to 16, Disabled
[ Z]
TIME OC
•
W1(3) PHASE TIME OC PICKUP: Enter the phase current level (in units of relay nominal
current) above which the winding 1(3) phase time overcurrent element will pickup and
start timing.
•
W1(3) PHASE TIME OC SHAPE: Select the time overcurrent curve shape to use for the
winging 1(3) phase time overcurrent. Time Overcurrent Curves on page 5–58 describes
the time overcurrent curve shapes.
•
W1(3) PHASE TIME OC MULTIPLIER: Enter the multiplier constant by which the
selected time overcurrent curve shape (the base curve) is to be shifted in time.
•
W1(3) PHASE TIME OC RESET: Select “Linear” reset to coordinate with
electromechanical time overcurrent relays, in which the reset characteristic (when the
current falls below the reset threshold before tripping) is proportional to ratio of
energy accumulated to that required to trip. Select “Instantaneous” reset to
coordinate with relays, such as most static units, with instantaneous reset
characteristics.
•
W1(3) HARMONIC DERATING CORRECTION: Select “Enabled” to enable automatic
harmonic derating correction of the winding 1(3) phase time overcurrent curve. The
745 calculates the derated transformer capability when supplying non-sinusoidal
load currents (as per ANSI / IEEE C57.110-1986) and, when this feature is enabled,
automatically shifts the phase time overcurrent curve pickup in order to maintain the
required protection margin with respect to the transformer thermal damage curve, as
illustrated below.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–63
SETPOINTSCHAPTER 5: SETPOINTS
time
Transformer thermal
damage curve
Selected relay time
overcurrent curve
Transformer thermal
protection margin
current
Pickup setting based
rated load capability
Pickup shifted based
on harmonic derating
FIGURE 5–15: Harmonic derating correction
FIGURE 5–16: Phase time overcurrent scheme logic
5–64
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
5.6.5.4 Winding 1 to 3 Phase Instantaneous Overcurrent
PATH: SETPOINTS ZV S4 ELEMENTS ZV PHASE OC ZV W1(3) PHASE INST OC 1(2)
„ W1 PHASE
W1 PHASE INST OC 1
FUNCTION: Enabled
Range:
Enabled, Disabled
MESSAGE
W1 PHASE INST OC 1
RLYS (1-8): --------
Range:
1 to 8
MESSAGE
W1 PHASE INST OC 1
TARGET: Latched
Range:
Self-Reset, Latched, None
MESSAGE
W1 PHASE INST OC 1
PICKUP: 10.00 x CT
Range:
0.05 to 20.00 x CT in steps of
0.01
MESSAGE
W1 PHASE INST OC 1
DELAY: 0 ms
Range:
0 to 60000 ms in steps of 1
MESSAGE
W1 PHASE INST OC 1
BLOCK: Disabled
Range:
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
[Z]
INST OC 1
Note
•
W1(3) PHASE INST OC 1(2) PICKUP: Enter the level of phase current (in units of relay
nominal current) above which the winding 1(3) phase instantaneous overcurrent 1
element will pickup and start the delay timer.
•
W1(3) PHASE INST OC 1(2) DELAY: Enter the time that the phase current must remain
above the pickup level before the element operates.
The setpoint messages above and the following logic diagram are identical for the
phase instantaneous overcurrent 2 element.
FIGURE 5–17: Phase instantaneous overcurrent 1 scheme logic
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–65
SETPOINTSCHAPTER 5: SETPOINTS
5.6.6
Neutral overcurrent
5.6.6.1 Main menu
PATH: SETPOINTS ZV S4 ELEMENTS ZV NEUTRAL OC
„ NEUTRAL OC
[Z]
„ W1 NTRL
[ Z]
TIME OC
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
„ W2 NTRL
[ Z]
TIME OC
„ W3 NTRL
[ Z]
TIME OC
„ W1 NTRL
[ Z]
INST OC 1
„ W2 NTRL
[ Z]
INST OC 1
„ W3 NTRL
[ Z]
INST OC 1
„ W1 NTRL
[ Z]
INST OC 2
„ W2 NTRL
[ Z]
INST OC 2
„ W3 NTRL
[ Z]
INST OC 2
See page 5–66
See page 5–66
See page 5–66
See page 5–68
See page 5–68
See page 5–68
See page 5–68
See page 5–68
See page 5–68
In the 745, “neutral” refers to residual current (3I0), calculated internally as the vector sum
of the three phases. The relay includes neutral time overcurrent and two levels of neutral
instantaneous overcurrent for each winding.
5.6.6.2 Neutral Time Overcurrent
PATH: SETPOINTS ZV S4 ELEMENTS ZV NEUTRAL OC ZV W1(3) NTRL TIME OC
„ W1 NTRL
W1 NEUTRAL TIME OC
FUNCTION: Enabled
Range:
Enabled, Disabled
MESSAGE
W1 NEUTRAL TIME OC
RLYS (1-8): --------
Range:
1 to 8
MESSAGE
W1 NEUTRAL TIME OC
TARGET: Latched
Range:
Self-Reset, Latched, None
MESSAGE
W1 NEUTRAL TIME OC
PICKUP: 0.85 x CT
Range:
0.05 to 20.00 x CT in steps of
0.01
MESSAGE
W1 NEUTRAL TIME OC
SHAPE: Ext Inverse
Range:
see description below
MESSAGE
W1 NEUTRAL TIME OC
MULTIPLIER: 1.00
Range:
0.00 to 100.00 in steps of 0.01
MESSAGE
W1 NEUTRAL TIME OC
RESET: Linear
Range:
Instantaneous, Linear
MESSAGE
W1 NEUTRAL TIME OC
BLOCK: Disabled
Range:
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
[Z]
TIME OC
5–66
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
•
W1(3) NEUTRAL TIME OC PICKUP: Enter the level of neutral current (in units of relay
nominal current) above which the winding 1(3) neutral time overcurrent element will
pickup and start timing.
•
W1(3) NEUTRAL TIME OC SHAPE: Select the time overcurrent curve shape to be used
for the winding 1(3) neutral time overcurrent element. The Time Overcurrent Curves on
page 5–58 describe the time overcurrent curve shapes.
•
W1(3) NEUTRAL TIME OC MULTIPLIER: Enter the multiplier constant by which the
selected time overcurrent curve shape (the base curve) is to be shifted in time.
•
W1(3) NEUTRAL TIME OC RESET: Select “Linear” reset to coordinate with
electromechanical time overcurrent relays, in which the reset characteristic (when the
current falls below the reset threshold before tripping) is proportional to ratio of
energy accumulated to that required to trip. Select “Instantaneous” reset to
coordinate with relays, such as most static units, with instantaneous reset
characteristics.
FIGURE 5–18: Neutral time overcurrent scheme logic
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–67
SETPOINTSCHAPTER 5: SETPOINTS
5.6.6.3 Neutral Instantaneous Overcurrent
PATH: SETPOINTS ZV S4 ELEMENTS ZV NEUTRAL OC ZV W1(3) NTRL INST OC 1(2)
„ W1 NTRL
W1 NEUTRAL INST OC 1
FUNCTION: Enabled
Range:
Enabled, Disabled
MESSAGE
W1 NEUTRAL INST OC 1
RLYS (1-8): --------
Range:
1 to 8
MESSAGE
W1 NEUTRAL INST OC 1
TARGET: Latched
Range:
Self-Reset, Latched, None
MESSAGE
W1 NEUTRAL INST OC 1
PICKUP: 10.00 x CT
Range:
0.05 to 20.00 x CT in steps of
0.01
MESSAGE
W1 NEUTRAL INST OC 1
DELAY: 0 ms
Range:
0 to 60000 ms in steps of 1
MESSAGE
W1 NEUTRAL INST OC 1
BLOCK: Disabled
Range:
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
[Z]
INST OC 1
Note
•
W1(3) NEUTRAL INST OC 1(2) PICKUP: Enter the level of neutral current (in units of
relay nominal current) above which the winding 1(3) neutral instantaneous
overcurrent 1 element will pickup and start the delay timer.
•
W1(3) NEUTRAL INST OC 1(2) DELAY: Enter the time that the neutral current must
remain above the pickup level before the element operates.
The setpoint messages above and the following logic diagram are identical for the
neutral instantaneous overcurrent 2 element.
FIGURE 5–19: Neutral instantaneous overcurrent scheme logic
5–68
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
5.6.7
Ground Overcurrent
5.6.7.1 Main Menu
PATH: SETPOINTS ZV S4 ELEMENTS ZV GROUND OC
„ GROUND OC
[ Z]
„ W1 GND
[Z]
TIME OC
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
„ W2 GND
[Z]
TIME OC
„ W3 GND
[Z]
TIME OC
„ W1 GND
[Z]
INST OC 1
„ W2 GND
[Z]
INST OC 1
„ W3 GND
[Z]
INST OC 1
„ W1 GND
[Z]
INST OC 2
„ W2 GND
[Z]
INST OC 2
„ W3 GND
INST OC 2
[Z]
See page 5–70
See page 5–70
See page 5–70
See page 5–71
See page 5–71
See page 5–71
See page 5–71
See page 5–71
See page 5–71
In the 745, “ground” refers to the current measured in a CT in the connection between the
transformer neutral and ground. The 745 has two ground inputs which could be assigned
to any of the three windings, based on the transformer type selected with respect to the
rules in table 3-2.
As the ground overcurrent settings corresponding to the winding-assigned ground inputs,
are displayed and enabled. This section contains the settings to configure the ground
overcurrent elements. Included are ground time overcurrents for each associated winding,
and two levels of ground instantaneous overcurrent for each associated winding.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–69
SETPOINTSCHAPTER 5: SETPOINTS
5.6.7.2 Ground Time Overcurrent
PATH: SETPOINTS ZV S4 ELEMENTS ZV GROUND OC Z W1(3) GND TIME OC
„ W1 GND
W1 GROUND TIME OC
FUNCTION: Enabled
Range:
Enabled, Disabled
MESSAGE
W1 GROUND TIME OC
RLYS (1-8): --------
Range:
1 to 8
MESSAGE
W1 GROUND TIME OC
TARGET: Latched
Range:
Self-Reset, Latched, None
MESSAGE
W1 GROUND TIME OC
PICKUP: 0.85 x CT
Range:
0.05 to 20.00 x CT in steps of
0.01
MESSAGE
W1 GROUND TIME OC
SHAPE: Ext Inverse
Range:
see description below
MESSAGE
W1 GROUND TIME OC
MULTIPLIER: 1.00
Range:
0.00 to 100.00 in steps of 0.01
MESSAGE
W1 GROUND TIME OC
RESET: Linear
Range:
Instantaneous, Linear
MESSAGE
W1 GROUND TIME OC
BLOCK: Disabled
Range:
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
[Z]
TIME OC
5–70
•
W1(3) GROUND TIME OC PICKUP: Enter the level of ground current (in units of relay
nominal current) above which the winding 1(3) ground time overcurrent element will
pickup and start timing.
•
W1(3) GROUND TIME OC SHAPE: Select the time overcurrent curve shape to be used
for the winding 1(3) ground time overcurrent element. Refer to Time Overcurrent
Curves on page 5–58 for a description of the time overcurrent curve shapes.
•
W1(3) GROUND TIME OC MULTIPLIER: Enter the multiplier constant by which the
selected time overcurrent curve shape (the base curve) is to be shifted in time.
•
W1(3) GROUND TIME OC RESET: Enter the multiplier constant by which the selected
time overcurrent curve shape (the base curve) is to be shifted in time.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
FIGURE 5–20: Ground time overcurrent scheme logic
5.6.7.3 Ground Instantaneous Overcurrent
PATH: SETPOINTS ZV S4 ELEMENTS ZV GROUND OC ZV W1(3) GROUND INST OC 1(2)
„ W1 GND
W1 GROUND INST OC 1
FUNCTION: Disabled
Range:
Enabled, Disabled
MESSAGE
W1 GROUND INST OC 1
RLYS (1-8): --------
Range:
1 to 8
MESSAGE
W1 GROUND INST OC 1
TARGET: Latched
Range:
Self-Reset, Latched, None
MESSAGE
W1 GROUND INST OC 1
PICKUP: 10.00 x CT
Range:
0.05 to 20.00 x CT in steps of
0.01
MESSAGE
W1 GROUND INST OC 1
DELAY: 0 ms
Range:
0 to 60000 ms in steps of 1
MESSAGE
W1 GROUND INST OC 1
BLOCK: Disabled
Range:
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
[Z]
INST OC 1
Note
•
W1(3) GROUND INST OC 1(2) PICKUP: Enter the level of ground current (in units of
relay nominal current) above which the winding 1(3) ground instantaneous
overcurrent 1 element will pickup and start the delay timer.
•
W1(3) GROUND INST OC 1(2) DELAY: Enter the time that the ground current must
remain above the pickup level before the element operates.
The messages above and scheme logic below are identical for windings 2 and 3 of
ground instantaneous overcurrent 1 and all windings on the ground instantaneous
overcurrent 2 element.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–71
SETPOINTSCHAPTER 5: SETPOINTS
FIGURE 5–21: Ground instantaneous overcurrent scheme logic
5.6.8
Restricted Ground Fault
PATH: SETPOINTS ZV S4 ELEMENTS ZV RESTRICTED GROUND Z W1(3) RESTD GND FAULT
W1 RESTD GND FAULT
FUNCTION: Disabled
Range:
Enabled, Disabled
MESSAGE
W1 RESTD GND FAULT
RLYS (1-8): --------
Range:
1 to 8
MESSAGE
W1 RESTD GND FAULT
TARGET: Latched
Range:
Self-Reset, Latched, None
MESSAGE
W1 RESTD GND FAULT
PICKUP: 0.08 x CT
Range:
0.02 to 20.00 x CT in steps of
0.01
MESSAGE
W1 RESTD GND FAULT
SLOPE: 10%
Range:
0 to 100% in steps of 1
MESSAGE
W1 RESTD GND FAULT
DELAY: 0.10 s
Range:
0.00 to 600.00 s in steps of 0.01
MESSAGE
W1 RESTD GND FAULT
BLOCK: Disabled
Range:
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
„ W1 RESTD GND [Z]
FAULT
Restricted ground fault protection is often applied to transformers having impedance
grounded wye. It is intended to provide sensitive ground fault detection for low magnitude
fault currents which would not be detected by the percent differential element.
87T
Rg
87TG
FIGURE 5–22: Restricted earth ground fault protection
5–72
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
Delta Winding
Wye Winding
IP
FAULT
Impedance grounded
wye winding
IF
FIGURE 5–23: Resistance grounded wye wiring
An internal ground fault on an impedance grounded wye winding (see second figure
above) produces a fault current (IF) dependent on the value of the ground impedance and
the position of the fault on the winding with respect to the neutral point. The resultant
primary current (IP) will be negligible for faults on the lower 30% of the winding since the
fault voltage will not be the system voltage but the result of the transformation ratio
between the primary windings and the percentage of shorted turns on the secondary.
Therefore, the resultant differential currents could be below the slope threshold of the
percent differential element and thus the fault could go undetected. The graph below
shows the relationship between the primary (IP) and fault (IF) currents as a function of the
distance of the fault point from the neutral and FIGURE 5–25: RGF and percent differential
zones of protection outlines the zones of effective protection along the winding for an
impedance grounded wye.
100
90
80
% Max Ifault
70
60
Ifault
50
40
30
Ip
20
Ip(x)
10
Ifault(x)
0
0
10
20
30
40
50
60
70
80
90
100
x = distance of fault from neutral
FIGURE 5–24: Fault currents vs. points from neutral
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–73
SETPOINTSCHAPTER 5: SETPOINTS
WINDING
35%
RGF
ZONE
DIFFERENTIAL
ZONE
Rg
FIGURE 5–25: RGF and percent differential zones of protection
The 745 implementation of restricted ground fault (shown below) is a low impedance
current differential scheme where “spill” current due to CT tolerances is handled via load
bias similar to the percent differential. The 745 calculates the vectorial difference of the
residual and ground currents (i.e. 3I0 - Ig) and divides this by the maximum line current
(Imax) to produce a percent slope value. The slope setting allows the user to determine the
sensitivity of the element based on the class and quality of the CTs used. Typically no more
than 4% overall error due to CT “spill” is assumed for protection class CTs at nominal load.
Note
The restricted ground fault protection is also available for delta windings with ground
inputs as shown in table 3.2.
Ia
Calculate
Maximum Phase
Current
Imax
Ib
Ic
Calculate
3I0
AND
Calculate
|3I0 – Ig|
Ig
745 RELAY
Slope = Igd/Imax
Slope > Setpoint
Timer
0 to 0.5 s
OUTPUT
Igd
Igd > Setpoint
Measure
Ig
FIGURE 5–26: Restricted ground fault implementation
The issue of maloperation due to heavy external faults resulting in CT saturation is handled
by a programmable timer. The timer provides the necessary delay for the external fault to
be cleared by the appropriate external protection with the added benefit that if the RGF
element remains picked up after the timer expires, the 745 operates and clears the fault.
This approach provides backup protection. Since the restricted ground fault element is
targeted at detecting low magnitude internal winding fault currents, the time delay for
internal faults is of little consequence, since sensitivity and security are the critical
parameters.
For example, consider a transformer with the following specifications:
5–74
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
10 MVA, 33 kV to 11 kV, 10% impedance, delta/wye 30,
Rg = 6.3 ohms,
Phase CT ratio = 600 / 1 A,
Rated load current Irated = 10 MVA / ( 3 × 11 kV) = 525 A,
Maximum phase-to-ground fault current Igf(max) = 11 kV / ( 3 × 6.3) = 1000 A.
For a winding fault point at 5% distance from the neutral:
I fault = 0.05 × I gf ( max ) = 0.05 × 1000 A = 50 A
(EQ 5.10)
From FIGURE 5–24: Fault currents vs. points from neutral on page 5–73, we see that the Ip
increase due to the fault is negligible and therefore 3Io = 0 (approximately). Therefore, the
maximum phase current = Imax = Irated = 525 A (approximately), and
I fault
- = 0 – 50
----------A- = 0.08 × CT = pickup setting
I gd = 3I 0 – I g = 0 – ------------------------------------------phase CT primary
600
I gd
(EQ 5.11)
50 A- = 9.5% (select slope setting = 9%)
Slope = ---------- = ------------I max
525 A
Time delay: dependent on downstream protection coordination (100 ms typical)
The winding 1 restricted ground fault setpoints are described below:
•
W1(3) RESTD GND FAULT PICKUP: Enter the minimum level of ground differential
current (in units of phase CT primary associated with the winding, where the restricted
ground fault is set) for the winding 1(3) restricted ground fault element.
•
W1(3) RESTD GND FAULT SLOPE: Enter a slope percentage (of ground differential
current to maximum line current).
•
W1(3) RESTD GND FAULT DELAY: Enter the time that the winding 1(3) restricted
ground fault element must remain picked up before the element operates.
FIGURE 5–27: Restricted ground fault scheme logic
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–75
SETPOINTSCHAPTER 5: SETPOINTS
5.6.9
Negative Sequence Overcurrent
5.6.9.1 Main Menu
PATH: SETPOINTS ZV S4 ELEMENTS ZV NEG SEQ OC
„ NEG SEQ OC
[ Z]
„ W1 NEG SEQ
[ Z]
TIME OC
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
„ W2 NEG SEQ
[ Z]
TIME OC
„ W3 NEG SEQ
[ Z]
TIME OC
„ W1 NEG SEQ
[ Z]
INST OC
„ W2 NEG SEQ
[ Z]
INST OC
„ W3 NEG SEQ
[ Z]
INST OC
See page 5–76
See page 5–76
See page 5–76
See page 5–77
See page 5–77
See page 5–77
This section contains the settings to configure the negative sequence overcurrent
elements. Included are negative sequence time overcurrents for each winding, and
negative sequence instantaneous overcurrents for each winding.
5.6.9.2 Negative Sequence Time Overcurrent
PATH: SETPOINTS ZV S4 ELEMENTS ZV NEG SEQ OC Z W1(3) NEG SEQ TIME OC
„ W1 NEG SEQ
W1 NEG SEQ TIME OC
FUNCTION: Enabled
Range:
Enabled, Disabled
MESSAGE
W1 NEG SEQ TIME OC
RLYS (1-8): --------
Range:
1 to 8
MESSAGE
W1 NEG SEQ TIME OC
TARGET: Latched
Range:
Self-Reset, Latched, None
MESSAGE
W1 NEG SEQ TIME OC
PICKUP: 0.25 x CT
Range:
0.05 to 20.00 x CT in steps of
0.01
MESSAGE
W1 NEG SEQ TIME OC
SHAPE: Ext Inverse
Range:
see description below
MESSAGE
W1 NEG SEQ TIME OC
MULTIPLIER: 1.00
Range:
0.00 to 100.00 in steps of 0.01
MESSAGE
W1 NEG SEQ TIME OC
RESET: Linear
Range:
Instantaneous, Linear
MESSAGE
W1 NEG SEQ TIME OC
BLOCK: Disabled
Range:
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
[ Z]
TIME OC
5–76
•
W1 (3) NEG SEQ TIME OC PICKUP: Enter the level of negative sequence current (in
units of relay nominal current) above which the winding 1(3) negative sequence time
overcurrent element will pickup and start timing.
•
W1 (3) NEG SEQ TIME OC SHAPE: Select the time overcurrent curve shape to be used
for the winding 1(3) negative sequence time overcurrent element. Refer to Time
Overcurrent Curves on page 5–58 for a description of the time overcurrent curve
shapes.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
•
W1 (3) NEG SEQ TIME OC MULTIPLIER: Enter the multiplier constant by which the
selected time overcurrent curve shape (the base curve) is to be shifted in time.
•
W1 (3) NEG SEQ TIME OC RESET: Select the “Linear” reset to coordinate with
electromechanical time overcurrent relays, in which the reset characteristic (when the
current falls below the reset threshold before tripping) is proportional to ratio of
“energy” accumulated to that required to trip. Select the “Instantaneous” reset to
coordinate with relays, such as most static units, with instantaneous reset
characteristics.
FIGURE 5–28: Negative sequence time overcurrent scheme logic
5.6.9.3 Negative Sequence Instantaneous Overcurrent
PATH: SETPOINTS ZV S4 ELEMENTS ZV NEG SEQ OC ZV W1(3) NEG SEQ INST OC
„ W1 NEG SEQ
W1 NEG SEQ INST OC
FUNCTION: Disabled
Range:
Enabled, Disabled
MESSAGE
W1 NEG SEQ INST OC
RLYS (1-8): --------
Range:
1 to 8
MESSAGE
W1 NEG SEQ INST OC
TARGET: Latched
Range:
Self-Reset, Latched, None
MESSAGE
W1 NEG SEQ INST OC
PICKUP: 10.00 x CT
Range:
0.05 to 20.00 x CT in steps of
0.01
MESSAGE
W1 NEG SEQ INST OC
DELAY: 0 ms
Range:
0 to 60000 ms in steps of 1
MESSAGE
W1 NEG SEQ INST OC
BLOCK: Disabled
Range:
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
[ Z]
INST OC
•
W1(3) NEG SEQ INST OC PICKUP: Enter the level of negative sequence current (in units
of relay nominal current) above which the winding 1(3) negative sequence
instantaneous overcurrent element will pickup and start the delay timer.
•
W1(3) NEG SEQ INST OC DELAY: Enter the time that the negative sequence current
must remain above the pickup level before the element operates.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–77
SETPOINTSCHAPTER 5: SETPOINTS
FIGURE 5–29: Negative sequence instantaneous overcurrent logic
5.6.10 Frequency
5.6.10.1 Main Menu
PATH: SETPOINTS ZV S4 ELEMENTS ZV FREQUENCY
„ FREQUENCY
[Z]
„ UNDERFREQUENCY [Z]
1
MESSAGE
MESSAGE
MESSAGE
„ UNDERFREQUENCY [Z]
2
„ FREQUENCY
[Z]
DECAY
„ OVERFREQUENCY [Z]
See page 5–79
See page 5–79
See page 5–80
See page 5–82
The 745 can be used as the primary detecting relay in automatic load shedding schemes
based on underfrequency. This need arises if, during a system disturbance, an area
becomes electrically isolated from the main system and suffers generation deficiency due
to loss of either transmission or generation facilities. If reserve generation is not available
in the area, conditions of low system frequency occur that may lead to a complete
collapse. The 745 provides a means of automatically disconnecting sufficient load to
restore an acceptable balance between load and generation.
The 745 uses both frequency and frequency rate-of-change as the basis for its operating
criteria. These measured values are based on the voltage input or, if voltage is disabled, the
winding 1 phase A current input. The relay has two (2) underfrequency and four (4) rate-ofchange levels. Thus, four or more separate blocks of load can be shed, according to the
severity of the disturbance.
In addition to these elements, the 745 has an overfrequency element. A significant
overfrequency condition, likely caused by a breaker opening and disconnecting load from
a particular generation location, can be detected and used to quickly ramp the turbine
speed back to normal. If this is not done, the overspeed can lead to a turbine trip which
would require a turbine start up before restoring the system. If the turbine speed can be
controlled successfully, system restoration can be much quicker. The overfrequency
element of the 745 can be used for this purpose at a generating location.
5–78
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
We strongly recommend the use of either the voltage, current, or both, signals for
supervision. If no supervising conditions are enabled, the element could produce
undesirable operation!
Note
5.6.10.2 Underfrequency
PATH: SETPOINTS ZV S4 ELEMENTS ZV FREQUENCY Z UNDERFREQUENCY 1(2)
UNDERFREQUENCY 1
FUNCTION: Disabled
Range:
Enabled, Disabled
MESSAGE
UNDERFREQUENCY 1
RLYS (1-8): --------
Range:
1 to 8
MESSAGE
UNDERFREQUENCY 1
TARGET: Self-Reset
Range:
Self-Reset, Latched, None
MESSAGE
CURRENT SENSING:
Enabled
Range:
Enabled, Disabled
MESSAGE
MINIMUM OPERATING
CURRENT: 0.20 x CT
Range:
0.05 to 1.00 x CT in steps of
0.01
MESSAGE
MINIMUM OPERATING
VOLTAGE: 0.50 x VT
Range:
0.10 to 0.99 x CT in steps of
0.01
MESSAGE
UNDERFREQUENCY 1
PICKUP: 59.00 Hz
Range:
45.00 to 59.99 Hz in steps of
0.01
MESSAGE
UNDERFREQUENCY 1
DELAY: 1.00 s
Range:
0.00 to 600.00 s in steps of 0.01
MESSAGE
UNDERFREQUENCY 1
BLOCK: Disabled
Range:
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
„ UNDERFREQUENCY [Z]
1
•
MINIMUM OPERATING CURRENT: Enter the minimum value of winding 1 phase A
current (in units of relay nominal current) required to allow the underfrequency
element to operate.
•
MINIMUM OPERATING VOLTAGE: Enter the minimum value of voltage (in units of relay
nominal voltage) required to allow the underfrequency element to operate.
•
UNDERFREQUENCY 1(2) PICKUP: Enter the frequency (in Hz) below which the
underfrequency 1 element will pickup and start the delay timer.
•
UNDERFREQUENCY 1(2) DELAY: Enter the time the frequency remains below the
pickup level before element operation.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–79
SETPOINTSCHAPTER 5: SETPOINTS
FIGURE 5–30: Underfrequency 1 scheme logic
5.6.10.3 Frequency Decay
PATH: SETPOINTS ZV S4 ELEMENTS ZV FREQUENCY ZV FREQUENCY DECAY
„ FREQUENCY
FREQUENCY DECAY
FUNCTION: Disabled
Range:
Enabled, Disabled
MESSAGE
FREQUENCY DECAY
RLYS (1-8): --------
Range:
1 to 8
MESSAGE
FREQUENCY DECAY
TARGET: Self-Reset
Range:
Self-Reset, Latched, None
MESSAGE
CURRENT SENSING:
Enabled
Range:
Enabled, Disabled
MESSAGE
MINIMUM OPERATING
CURRENT: 0.20 x CT
Range:
0.05 to 1.00 x CT in steps of
0.01
MESSAGE
MINIMUM OPERATING
VOLTAGE: 0.50 x VT
Range:
0.10 to 0.99 x CT in steps of
0.01
MESSAGE
FREQUENCY DECAY
THRESHOLD: 59.50 Hz
Range:
45.00 to 59.99 Hz in steps of
0.01
MESSAGE
FREQUENCY DECAY
DELAY: 0.00 s
Range:
0.00 to 600.00 s in steps of 0.01
MESSAGE
FREQUENCY DECAY
RATE 1: 0.4 Hz/s
Range:
0.1 to 5.0 Hz/s in steps of 0.1
[Z]
DECAY
5–80
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
MESSAGE
FREQUENCY DECAY
RATE 2: 1.0 Hz/s
Range:
0.1 to 5.0 Hz/s in steps of 0.1
MESSAGE
FREQUENCY DECAY
RATE 3: 2.0 Hz/s
Range:
0.1 to 5.0 Hz/s in steps of 0.1
MESSAGE
FREQUENCY DECAY
RATE 4: 4.0 Hz/s
Range:
0.1 to 5.0 Hz/s in steps of 0.1
MESSAGE
FREQUENCY DECAY
BLOCK: Disabled
Range:
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
•
MINIMUM OPERATING CURRENT: Enter the minimum value of winding 1 phase A
current (in units of relay nominal current) required to allow the frequency decay
element to operate.
•
MINIMUM OPERATING VOLTAGE: Enter the minimum value of voltage (in units of relay
nominal voltage) required to allow the underfrequency element to operate.
•
FREQUENCY DECAY THRESHOLD: Enter the frequency (in Hz) below which the four
frequency rate of change levels of the frequency decay element will be allowed to
operate.
•
FREQUENCY DECAY RATE 1(4): Enter the rate of frequency decay beyond which the
corresponding element operates.
FIGURE 5–31: Frequency decay scheme logic
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–81
SETPOINTSCHAPTER 5: SETPOINTS
5.6.10.4 Overfrequency
PATH: SETPOINTS ZV S4 ELEMENTS ZV FREQUENCY ZV OVERFREQUENCY 1(2)
OVERFREQUENCY
FUNCTION: Disabled
Range:
Enabled, Disabled
MESSAGE
OVERFREQUENCY
RLYS (1-8): --------
Range:
1 to 8
MESSAGE
OVERFREQUENCY
TARGET: Latched
Range:
Self-Reset, Latched, None
MESSAGE
CURRENT SENSING:
Enabled
Range:
Enabled, Disabled
MESSAGE
MINIMUM OPERATING
CURRENT: 0.20 x CT
Range:
0.05 to 1.00 x CT in steps of
0.01
MESSAGE
MINIMUM OPERATING
VOLTAGE: 0.50 x VT
Range:
0.10 to 0.99 x CT in steps of
0.01
MESSAGE
OVERFREQUENCY
PICKUP: 60.50 Hz
Range:
50.01 to 65.00 Hz in steps of
0.01
MESSAGE
OVERFREQUENCY
DELAY: 5.00 s
Range:
0.00 to 600.00 s in steps of 0.01
MESSAGE
OVERFREQUENCY
BLOCK: Disabled
Range:
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
„ OVERFREQUENCY [Z]
5–82
•
MINIMUM OPERATING CURRENT: Enter the minimum value of winding 1 phase A
current (in units of relay nominal current) required to allow the overfrequency element
to operate.
•
MINIMUM OPERATING VOLTAGE: Enter the minimum voltage value (in units of relay
nominal voltage) required to allow overfrequency to operate.
•
OVERFREQUENCY PICKUP: Enter the frequency (in Hz) above which the overfrequency
element will pickup and start the delay timer.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
•
OVERFREQUENCY DELAY: Enter the time that the frequency must remain above the
pickup level before the element operates.
FIGURE 5–32: Overfrequency scheme logic
5.6.11 Overexcitation
5.6.11.1 Main Menu
PATH: SETPOINTS ZV S4 ELEMENTS ZV OVEREXCITATION
„ OVEREXCITATION [Z]
„ 5th HARMONIC [Z]
LEVEL
MESSAGE
MESSAGE
„ VOLTS PER
[ Z]
HERTZ 1
„ VOLTS PER
HERTZ 2
[ Z]
See page 5–84
See page 5–85
See page 5–85
A transformer is designed to operate at or below a maximum magnetic flux density in the
transformer core. Above this design limit the eddy currents in the core and nearby
conductive components cause overheating which within a very short time may cause
severe damage. The magnetic flux in the core is proportional to the voltage applied to the
winding divided by the impedance of the winding. The flux in the core increases with either
increasing voltage or decreasing frequency. During startup or shutdown of generatorconnected transformers, or following a load rejection, the transformer may experience an
excessive ratio of volts to hertz, that is, become overexcited.
When a transformer core is overexcited, the core is operating in a non-linear magnetic
region, and creates harmonic components in the exciting current. A significant amount of
current at the 5th harmonic is characteristic of overexcitation.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–83
SETPOINTSCHAPTER 5: SETPOINTS
This section contains the settings to configure the overexcitation monitoring elements.
Included are a 5th harmonic level, and two volts-per-hertz elements, each with a pickup
level and a time delay.
5.6.11.2 Fifth Harmonic Level
PATH: SETPOINTS ZV S4 ELEMENTS ZV OVEREXCITATION Z 5th HARMONIC LEVEL
5th HARMONIC LEVEL
FUNCTION: Disabled
Range:
Enabled, Disabled
MESSAGE
5th HARMONIC LEVEL
RLYS (1-8): --------
Range:
1 to 8
MESSAGE
5th HARMONIC LEVEL
TARGET: Self-Reset
Range:
Self-Reset, Latched, None
MESSAGE
MINIMUM OPERATING
CURRENT: 0.10 x CT
Range:
0.03 to 1.00 x CT in steps of
0.01
MESSAGE
5th HARMONIC LEVEL
PICKUP: 10.0% fo
Range:
0.1 to 99.9% f0 in steps of 0.1
MESSAGE
5th HARMONIC LEVEL
DELAY: 10 s
Range:
0 to 60000 s in steps of 1
MESSAGE
5th HARMONIC LEVEL
BLOCK: Disabled
Range:
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
„ 5th HARMONIC [Z]
LEVEL
•
MINIMUM OPERATING CURRENT: Enter the minimum value of current (in units of relay
nominal current) required to allow the 5th harmonic level element to operate.
•
5TH HARMONIC LEVEL PICKUP: Enter the 5th harmonic current (in %ƒ0) above which
the 5th harmonic level element will pickup and start the delay timer.
•
5TH HARMONIC LEVEL DELAY: Enter the time that the 5th harmonic current must
remain above the pickup level before the element operates.
FIGURE 5–33: 5th harmonic level scheme logic
5–84
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
5.6.11.3 Volts per Hertz
PATH: SETPOINTS ZV S4 ELEMENTS ZV OVEREXCITATION ZV VOLTS PER HERTZ 1(2)
„ VOLTS PER
VOLTS-PER-HERTZ 1
FUNCTION: Disabled
Range:
Enabled, Disabled
MESSAGE
VOLTS-PER-HERTZ
RLYS (1-8): --------
Range:
1 to 8
MESSAGE
VOLTS-PER-HERTZ 1
TARGET: Self-Reset
Range:
Self-Reset, Latched, None
MESSAGE
MINIMUM OPERATING
VOLTAGE: 0.10 x VT
Range:
0.10 to 0.99 x VT in steps of
0.01
MESSAGE
VOLTS-PER-HERTZ 1
PICKUP: 2.36 V/Hz
Range:
1.00 to 4.00 V/Hz in steps of
0.01
MESSAGE
VOLTS-PER-HERTZ 1
SHAPE: Definite Time
Range:
Definite Time, Inv Curve 1, Inv
Curve 2, Inv Curve 3
MESSAGE
VOLTS-PER-HERTZ 1
DELAY: 2.00 s
Range:
0.00 to 600.00 s in steps of 0.01
MESSAGE
VOLTS-PER-HERTZ 1
RESET: 0.0 s
Range:
0.0 to 6000.0 s in steps of 0.1
MESSAGE
VOLTS-PER-HERTZ 1
BLOCK: Disabled
Range:
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
[ Z]
HERTZ 1
The volts per hertz element uses the ratio of the actual measured voltage at the voltage
terminal and the measured system frequency. For example, a measured phases-to-phase
voltage of 120 volts at 60 Hz, results in a ratio of 2 V/Hz. For 115% overload, the setting of
the volts per hertz minimum pickup would be 2.3 V/Hz.
The element has a linear reset characteristic. The reset time can be programmed to match
the cooling characteristic of the protected equipment. The element will fully reset after the
VOLTS-PER-HERTZ RESET value. The volts per hertz function can be used as an
instantaneous element with no intentional delay, as a definite time element, or as an
inverse timed element.
•
MINIMUM OPERATING VOLTAGE: Enter the minimum value of voltage (in terms of
nominal VT secondary voltage) required to allow the volts per hertz 1 element to
operate.
•
VOLTS-PER-HERTZ 1 PICKUP: Enter the volts per hertz value (in V/Hz) above which the
volts per hertz 1 element will pickup and start the delay timer.
•
VOLTS-PER-HERTZ 1 SHAPE: Select the curve shape to be used for the volts per hertz 1
element. The inverse volts per hertz curve shapes are shown below.
•
VOLTS-PER-HERTZ 1 DELAY: Enter the time that the volts per hertz value must remain
above the pickup level before the element operates.
•
VOLTS-PER-HERTZ 1 RESET: Enter the time that the volts per hertz value must remain
below the pickup level before the element resets.
The curve for the inverse curve 1 shape is derived from the formula:
D
T = --------------------------------V ⁄ F -⎞ 2
⎛ --------------–1
⎝ Pickup⎠
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
V
when --- > Pickup
F
(EQ 5.12)
5–85
SETPOINTSCHAPTER 5: SETPOINTS
where: T = operate time (in seconds)
D = delay setpoint (in seconds)
V = fundamental RMS value of voltage (V)
F = frequency of voltage signal (Hz)
Pickup = volts per hertz pickup setpoint (V/Hz)
1000
Time to Trip (seconds)
100
Time
Delay
Setting
ò
10
10
1
3
1
0.1
0.3
0.1
0.01
1.00
1.20
1.40
1.60
1.80
2.00
Multiples of Volts/Hertz Pickup
FIGURE 5–34: Volts per hertz curve 1
The curve for the inverse curve 2 shape is derived from the formula:
D
T = ------------------------V
⁄
F
---------------- – 1
Pickup
V
when --- > Pickup
F
(EQ 5.13)
where: T = operate time (in seconds)
D = delay setpoint (in seconds)
V = fundamental RMS value of voltage (V)
F = frequency of voltage signal (Hz)
Pickup = volts per hertz pickup setpoint (V/Hz)
1000
Time to Trip (seconds)
100
Time
Delay
Setting
10
10
3
1
1
0.3
0.1
1.00
0.1
1.20
1.40
1.60
1.80
2.00
Multiples of Volts/Hertz Pickup
FIGURE 5–35: Volts per hertz curve 2
5–86
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
The curve for the inverse curve 3 shape is derived from the formula:
D
T = -----------------------------------V ⁄ F ⎞ 0.5
⎛ --------------–1
⎝ Pickup⎠
where
V
when --- > Pickup
F
(EQ 5.14)
T = operate time (in seconds)
D = delay setpoint (in seconds)
V = fundamental RMS value of voltage (V)
F = frequency of voltage signal (Hz)
Pickup = volts-per-hertz pickup setpoint (V/Hz)
10000
Time to Trip (seconds)
1000
Time
Delay
Setting
ò
100
10
10
3
1
1
0.3
0.1
0.1
1.00
1.20
1.40
1.60
1.80
2.00
Multiples of Voltz/Hertz Pickup
FIGURE 5–36: Volts per hertz curve 3
FIGURE 5–37: Volts per hertz scheme logic
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–87
SETPOINTSCHAPTER 5: SETPOINTS
5.6.12 Harmonics
5.6.12.1 Main Menu
PATH: SETPOINTS ZV S4 ELEMENTS ZV HARMONICS
„ HARMONICS
[Z]
„ W1 THD LEVEL [Z]
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
„ W2 THD LEVEL [Z]
„ W3 THD LEVEL [Z]
„ W1 HARMONIC
[Z]
DERATING
„ W2 HARMONIC
[Z]
DERATING
„ W3 HARMONIC
[Z]
DERATING
See page 5–88
See page 5–88
See page 5–88
See page 5–89
See page 5–89
See page 5–89
This section contains the settings to configure the total harmonic distortion monitoring
elements. Included are a THD level element for each winding and each phase.
5.6.12.2 THD Level
PATH: SETPOINTS ZV S4 ELEMENTS ZV HARMONICS Z W1(3) THD LEVEL
W1 THD LEVEL
FUNCTION: Disabled
Range:
Enabled, Disabled
MESSAGE
W1 THD LEVEL
RLYS (1-8): --------
Range:
1 to 8
MESSAGE
W1 THD LEVEL
TARGET: Self-Reset
Range:
Self-Reset, Latched, None
MESSAGE
MINIMUM OPERATING
CURRENT: 0.10 x CT
Range:
0.03 to 1.00 x CT in steps of
0.01
MESSAGE
W1 THD LEVEL
PICKUP: 50.0% f0
Range:
0.1 to 50.0% f0 in steps of 0.1
MESSAGE
W1 THD LEVEL
DELAY: 10 s
Range:
0 to 60000 s in steps of 1
MESSAGE
W1 THD LEVEL
BLOCK: Disabled
Range:
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
„ W1 THD LEVEL [Z]
5–88
•
MINIMUM OPERATING CURRENT: Enter the minimum value of current (in units of relay
nominal current) required to allow the THD level element to operate.
•
W1(3) THD PICKUP LEVEL: Enter the total harmonic distortion (in %ƒ0) above which
the winding 1(3) total harmonic distortion element level will pickup and start the delay
timer.
•
W1(3) THD LEVEL DELAY: Enter the time that the total harmonic distortion must
remain above the pickup level before the element operates.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
FIGURE 5–38: THD level scheme logic
5.6.12.3 Harmonic Derating
PATH: SETPOINTS ZV S4 ELEMENTS ZV HARMONICS ZV W1(3) HARMONIC DERATING
„ W1 HARMONIC
W1 HARM DERATING
FUNCTION: Disabled
Range:
Enabled, Disabled
MESSAGE
W1 HARM DERATING
RLYS (1-8): --------
Range:
1 to 8
MESSAGE
W1 HARM DERATING
TARGET: Self-Reset
Range:
Self-Reset, Latched, None
MESSAGE
MINIMUM OPERATING
CURRENT: 0.10 x CT
Range:
0.03 to 1.00 x CT in steps of
0.01
MESSAGE
W1 HARM DERATING
PICKUP: 0.90
Range:
0.01 to 0.98 in steps of 0.01
MESSAGE
W1 HARM DERATING
DELAY: 10 s
Range:
0 to 60000 s in steps of 1
MESSAGE
W1 HARM DERATING
BLOCK: Disabled
Range:
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
[ Z]
DERATING
•
MINIMUM OPERATING CURRENT: Enter the minimum value of current (in units of relay
nominal current) required to allow the harmonic derating element to operate.
•
W1(3) HARMONIC DERATING PICKUP: Enter the harmonic derating below which the
winding 1(3) harmonic derating will pickup and start the delay timer.
•
W1(3) HARMONIC DERATING DELAY: Enter the time that the harmonic derating must
remain below the pickup level before the element operates.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–89
SETPOINTSCHAPTER 5: SETPOINTS
FIGURE 5–39: Harmonic derating scheme logic
5.6.13 Insulation Aging
5.6.13.1 Main Menu
PATH: SETPOINTS ZV S4 ELEMENTS ZV INSULATION AGING
„ INSULATION
[ Z]
„ HOTTEST-SPOT [Z]
AGING
LIMIT
MESSAGE
MESSAGE
„ AGING FACTOR [Z]
LIMIT
„ LOSS OF LIFE [Z]
LIMIT
See page 5–91
See page 5–92
See page 5–93
The 745 insulation aging / loss of life feature is based on the computational methods
presented in IEEE standards C57.91–1995, IEEE Guide for Loading Mineral-Oil-Immersed
Transformers, and C57.96–1989, IEEE Guide for Loading Dry-Type Distribution and Power
Transformers. These standards present a method of computing the top oil temperature,
the hottest spot inside the transformer, the aging factor, and the total accumulated loss of
life. The computations are based on the loading of the transformer, the ambient
temperature, and the transformer data entered. The computations assume that the
transformer cooling system is fully operational and able to maintain transformer
temperatures within the specified limits under normal load conditions.
The computation results are a guide only. The transformer industry has not yet been able
to define, with any degree of precision, the exact end of life of a transformer. Many
transformers are still in service today, though they have long surpassed their theoretical
end of life, some of them by a factor of three of four times.
5–90
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
Three protection elements are provided as part of the Loss of Life feature. The first element
monitors the hottest-spot temperature. The second element monitors the aging factor and
the third monitors the total accumulated loss of life. Each element produces an output
when the monitored quantity exceeds a set limit.
The insulation aging / loss of life feature is a field-upgradable feature. For the feature (and
associated elements) to operate correctly, it must first be enabled under the factory
settings using the passcode provided at purchase. If the feature was ordered when the
relay was purchased, then it is already enabled. Note that setting this feature using the
EnerVista 745 Setup software requires that it be enabled the under File > Properties >
Loss of Life menu. If the computer is communicating with a relay with the feature installed,
it is automatically detected.
For the computations to be performed correctly, it is necessary to enter the transformer
data under S2 SYSTEM SETUP Z TRANSFORMER. The transformer load is taken from the
winding experiencing the greatest loading. All transformer and winding setpoints must be
correct or the computations will be meaningless.
The preferred approach for ambient temperature is to use an RTD connected to the 745. If
this is not feasible, average values for each month of the year can be entered as settings,
under S2 SYSTEM SETUP ZV AMBIENT TEMPERATURE ZV AMBIENT RTD TYPE and selecting
“By Monthly Average”.
5.6.13.2 Hottest Spot Limit
PATH: SETPOINTS ZV S4 ELEMENTS ZV INSULATION AGING Z HOTTEST-SPOT LIMIT
HOTTEST-SPOT LIMIT
FUNCTION: Disabled
Range:
Enabled, Disabled
MESSAGE
HOTTEST-SPOT LIMIT
RLYS (1-8): --------
Range:
1 to 8
MESSAGE
HOTTEST-SPOT LIMIT
TARGET: Self-Reset
Range:
Self-Reset, Latched, None
MESSAGE
HOTTEST-SPOT LIMIT
PICKUP: 150°C
Range:
50 to 300°C in steps of 1
MESSAGE
HOTTEST-SPOT LIMIT
DELAY: 10 min
Range:
0 to 60000 min. in steps of 1
MESSAGE
HOTTEST-SPOT LIMIT
BLOCK: Disabled
Range:
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
„ HOTTEST-SPOT [Z]
LIMIT
The hottest-spot limit element provides a means of detecting an abnormal hot spot inside
the transformer. The element operates on the computed hottest-spot value. The hottestspot temperature will revert to 0°C for 1 minute if the power supply to the relay is
interrupted.
•
HOTTEST SPOT LIMIT PICKUP: Enter the hottest-spot temperature required for
operation of the element. This setting should be a few degrees above the maximum
permissible hottest-spot temperature under emergency loading condition and
maximum ambient temperature.
•
HOTTEST SPOT LIMIT DELAY: Enter a time delay above which the hottest-spot
temperature must remain before the element operates.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–91
SETPOINTSCHAPTER 5: SETPOINTS
FIGURE 5–40: Hottest-spot limit scheme logic
5.6.13.3 Aging factor limit
PATH: SETPOINTS ZV S4 ELEMENTS ZV INSULATION AGING ZV AGING FACTOR LIMIT
AGING FACTOR LIMIT
FUNCTION: Disabled
Range:
Enabled, Disabled
MESSAGE
AGING FACTOR LIMIT
RLYS (1-8): --------
Range:
1 to 8
MESSAGE
AGING FACTOR LIMIT
TARGET: Self-Reset
Range:
Self-Reset, Latched, None
MESSAGE
AGING FACTOR LIMIT
PICKUP: 2.0
Range:
1.1 to 10.0 in steps of 0.1
MESSAGE
AGING FACTOR LIMIT
DELAY: 10 min
Range:
0 to 60000 min. in steps of 1
MESSAGE
AGING FACTOR LIMIT
BLOCK: Disabled
Range:
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
„ AGING FACTOR [Z]
LIMIT
The aging factor limit element provides a means of detecting when a transformer is aging
faster than would normally be acceptable. The element operates on the computed aging
factor, which in turn is derived from the computed hottest-spot value. The aging factor
value will revert to zero if the power supply to the relay is interrupted. The necessary
settings required for this element to perform correctly are entered under:
•
5–92
AGING FACTOR LIMIT PICKUP: Enter the aging factor required for operation of the
element. This setting should be above the maximum permissible aging factor under
emergency loading condition and maximum ambient temperature.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
•
AGING FACTOR LIMIT DELAY: Enter a time delay above which the aging factor must
remain before the element operates.
FIGURE 5–41: Aging factor limit scheme logic
5.6.13.4 Loss of Life Limit
PATH: SETPOINTS ZV S4 ELEMENTS ZV INSULATION AGING ZV LOSS OF LIFE LIMIT
LOSS OF LIFE LIMIT
FUNCTION: Disabled
Range:
Enabled, Disabled
MESSAGE
LOSS OF LIFE LIMIT
RLYS (1-8): --------
Range:
1 to 8
MESSAGE
LOSS OF LIFE LIMIT
TARGET: Self-Reset
Range:
Self-Reset, Latched, None
MESSAGE
LOSS OF LIFE LIMIT
PICKUP: 16000 x 10h
Range:
0 to 20000 x 10h (a maximum
of 20000 hrs.) in steps of 1
MESSAGE
LOSS OF LIFE LIMIT
BLOCK: Disabled
Range:
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
„ LOSS OF LIFE [Z]
LIMIT
The loss of life limit element computes the total expended life of the transformer, based on
the aging factor and the actual in-service time of the transformer. For example, if the aging
factor is a steady 1.5 over a time period of 10 hours, the transformer will have aged for an
equivalent 1.5 × 10 = 15 hours. The cumulative total number of hours expended is retained
in the relay even when control power is lost. The initial loss of life value, when a relay is first
placed in service, can be programmed under the transformer settings. The element
operates on the cumulative total value, with no time delay. The output of this element
should be used as an alarm only, as users may wish to leave the transformer in service
beyond the theoretical expended life.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–93
SETPOINTSCHAPTER 5: SETPOINTS
Enter the expended life, in hours, required for operation of the element in the LOSS OF LIFE
PICKUP setpoint. This setting should be above the total life of the transformer, in hours. As
an example, for a 15-year transformer, the total number of hours would be 13140 × 10 =
131400 hours.
Note
The actual values are only displayed if the loss of life option is installed and the
ambient temperature is enabled.
FIGURE 5–42: Loss-of-life scheme logic
5.6.14 Analog Input Level
PATH: SETPOINTS ZV S4 ELEMENTS ZV ANALOG INPUT Z ANALOG LEVEL 1(2)
ANALOG INPUT LEVEL 1
FUNCTION: Disabled
Range:
Enabled, Disabled
MESSAGE
ANALOG INPUT LEVEL 1
RLYS (1-8): --------
Range:
1 to 8
MESSAGE
ANALOG INPUT LEVEL 1
TARGET: Self-Reset
Range:
Self-Reset, Latched, None
MESSAGE
ANALOG INPUT LEVEL 1
PICKUP: 10 μA
Range:
1 to 65000 μA in steps of 1
MESSAGE
ANALOG INPUT LEVEL 1
DELAY: 50 s
Range:
0 to 60000 s in steps of 1
MESSAGE
ANALOG INPUT LEVEL 1
BLOCK: Disabled
Range:
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
„ ANALOG LEVEL 1 [Z]
The 745 can monitor any external quantity, such as bus voltage, battery voltage, etc., via a
general purpose auxiliary current input called the analog input. Any one of the standard
transducer output ranges 0 to 1 mA, 0 to 5 mA, 4 to 20 mA, or 0 to 20 mA can be
connected to the analog input terminals. The analog input is configured in S2 SYSTEM
SETUP ZV ANALOG INPUT and the actual values displayed in A2 METERING ZV ANALOG
INPUT.
5–94
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
FIGURE 5–43: Analog level scheme logic
5.6.15 Current Demand
PATH: SETPOINTS ZV S4 ELEMENTS ZV CURRENT DEMAND Z W1(3) CURRENT DEMAND
W1 CURRENT DEMAND
FUNCTION: Disabled
Range:
Enabled, Disabled
MESSAGE
W1 CURRENT DEMAND
RLYS (1-8): --------
Range:
1 to 8
MESSAGE
W1 CURRENT DEMAND
TARGET: Self-Reset
Range:
Self-Reset, Latched, None
MESSAGE
W1 CURRENT DEMAND
PICKUP: 100 A
Range:
0 to 100000 A in steps of 1
(auto-ranging)
MESSAGE
W1 CURRENT DEMAND
BLOCK: Disabled
Range:
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
„ CURRENT DEMAND [Z]
This section contains the settings to configure the current demand monitoring elements.
Included are a current demand level for each winding.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–95
SETPOINTSCHAPTER 5: SETPOINTS
FIGURE 5–44: Current demand scheme logic
5.6.16 Transformer Overload
PATH: SETPOINTS ZV S4 ELEMENTS ZV XFORMER OVERLOAD
„ XFORMER
TRANSFORMER OVERLOAD
FUNCTION: Disabled
Range:
Enabled, Disabled
MESSAGE
TRANSFORMER OVERLOAD
RLYS (1-8): --------
Range:
1 to 8
MESSAGE
TRANSFORMER OVERLOAD
TARGET: Self-Reset
Range:
Self-Reset, Latched, None
MESSAGE
TRANSFORMER OVERLOAD
PICKUP: 208% rated
Range:
50 to 300% of Rated Load in
steps of 1
MESSAGE
TRANSFORMER OVERLOAD
DELAY: 10 s
Range:
0 to 60000 s in steps of 1
MESSAGE
TRANSFORMER OVERLOAD
BLOCK: Disabled
Range:
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
MESSAGE
XFMR OVERTEMP ALARM
SIGNAL: Disabled
Range:
Disabled, Logc Inpt 1 to 16
[Z]
OVERLOAD
5–96
•
TRANSFORMER OVERLOAD PICKUP: This setting identifies the level of transformer
overload, where the pickup delay starts timing. The setting is expressed as a
percentage of the transformer base MVA rating, and is normally set at or above the
maximum rated MVA from the transformer nameplate.
•
XFMR OVERTEMP ALARM SIGNAL: Select any logic input that, when asserted,
indicates the transformer cooling system has failed and an over-temperature
condition exists. The logic input should be connected to the transformer winding
temperature alarm contacts.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
FIGURE 5–45: Transformer overload scheme logic
5.6.17 Tap Changer Failure
PATH: SETPOINTS ZV S4 ELEMENTS ZV TAP CHANGR FAILURE
„ TAP CHANGR
TAP CHANGER FAILURE
FUNCTION: Disabled
Range:
Enabled, Disabled
MESSAGE
TAP CHANGER FAILURE
RLYS (1-8): --------
Range:
1 to 8
MESSAGE
TAP CHANGER FAILURE
TARGET: Self-Reset
Range:
Self-Reset, Latched, None
MESSAGE
TAP CHANGER FAILURE
DELAY: 5.00 s
Range:
0.00 to 600.00 s in steps of 0.01
MESSAGE
TAP CHANGER FAILURE
BLOCK: Disabled
Range:
Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
[Z]
FAILURE
The tap changer failure element monitors the resistance seen by the tap changer
monitoring circuit. The element produces an output signal when the tap changer position
exceeds the maximum number of taps (set by the NUMBER OF TAP POSITIONS setpoint) by
two. This signal can be used as an alarm or as a signal to change the setpoint group. A
change in the setpoint group would be programmed through the FlexLogic™. This
approach would be useful if very sensitive settings had been used in the normal in-service
setpoint group for the harmonic restrained differential element, assuming that the tap
changer position was used to compensate the input current magnitude.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–97
SETPOINTSCHAPTER 5: SETPOINTS
FIGURE 5–46: Tap changer failure scheme logic
5–98
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
5.7
S5 Outputs
5.7.1
Description
The S5 OUTPUTS page contains the settings to configure all outputs. The 745 has nine
digital outputs (one solid-state, four trip-rated form A contacts, and four auxiliary form-C
contacts), which are fully programmable from the relay unit, as well using FlexLogic™
equations.
In addition to these outputs, the conditions to trigger a waveform capture (trace memory)
is also programmable using FlexLogic™. A ten parameter equation is provided for this
purpose.
5.7.2
Relay Assignments
As an alternative to FlexLogic™ programming, the output auxiliary relays can be assigned
directly from the element settings on the relay.
On the relay unit, every protection element settings page has a new setting to configure.
The position of the setting is right between the function and the target settings of the
element configuration. The relays selected from the elements page will be energized only
on the operate condition of the protection element.
This new setting allows the user to assign relays directly to the protection element. The
new settings have a default value for no relays assigned (None).
With the addition of the new setting, output relays can be energized from the protection
element setting OR the FlexLogic™.
As an example, the new setting in the Percent Differential element will look like PATH:
SETPOINTS ZV S4 ELEMENTS ZV DIFFERENTIAL Z PERCENT DIFFERENTIAL (section 5.6.3.2).
5.7.3
Introduction to FlexLogic™
FlexLogic™ is a highly flexible and easy-to-use equation format which allows any
combination of protection and monitoring elements, logic inputs, outputs, and timers to be
assigned to any output, using multiple input AND, OR, NAND, NOR, XOR, and NOT Boolean
logic gates. Each digital output can have an equation of up to 20 parameters. Five virtual
outputs are also available, each having an equation containing up to 10 parameters,
whose output can be used as a parameter in any other equation.
A FlexLogic™ equation defines the combination of inputs and logic gates to operate an
output. Each output has its own equation, an equation being a linear array of parameters.
Evaluation of an equation results in either a 1 (= ON, i.e. operate the output), or 0 (= OFF, i.e.
do not operate the output).
The table below provides information about FlexLogic™ equations for all outputs:
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–99
SETPOINTSCHAPTER 5: SETPOINTS
Table 5–10: FlexLogic™ output types
Name
Type
Equation
parameters
Evaluation rate
Output relay 1
solid-state
20
Output relays 2 to 5
trip-rated form-A contacts
20 each
every 1/2 cycle*
every 1/2 cycle*
Output relays 6 to 8
form-C contacts
20 each
every 100 ms
Self-test relay
form-C contacts dedicated for
self-test (not programmable)
---
every 100 ms
Trace trigger
waveform capture trigger
10
every 1/2 cycle*
Virtual outputs
internal register (for use in
other equations)
10 each
every 1/2 cycle*
* refers to the power system cycle as detected by the frequency circuitry of the 745.
As mentioned above, the parameters of an equation can contain either INPUTS or GATES.
Table 5–11: FlexLogic™ input types
Inputs
Input is “1” (= ON) if...
Element* pickup
The pickup setting of the element is exceeded
Element* operate
The pickup setting of the element is exceeded for the programmed
time delay
Logic inputs 1 to 16
The logic input contact is asserted
Virtual inputs 1 to 16
The virtual input is asserted
Output relays 1 to 8
The output relay operates
(i.e. evaluation of the FlexLogic™ equation results in a ‘1’)
Virtual outputs 1 to 5
The virtual output operates
(i.e. evaluation of the FlexLogic™ equation results in a ‘1’)
Timers 1 to 10
The timer runs to completion
(i.e. the ‘start’ condition is met for the programmed time delay)
* refers to any protection or monitoring element in page S4 ELEMENTS.
Table 5–12: FlexLogic™ gates
Gates
Number of inputs
Output is “1” (= ON) if...
NOT
1
input is ‘0’
OR
2 to 19 (for 20 equation parameters)
2 to 9 (for 10 equation parameters)
any input is ‘1’
AND
2 to 19 (for 20 equation parameters)
2 to 9 (for 10 equation parameters)
all inputs are ‘1’
NOR
2 to 19 (for 20 equation parameters)
2 to 9 (for 10 equation parameters)
all inputs are ‘0’
NAND
2 to 19 (for 20 equation parameters)
2 to 9 (for 10 equation parameters)
any input is ‘0’
XOR
2 to 19 (for 20 equation parameters)
2 to 9 (for 10 equation parameters)
odd number of inputs are ‘1’
Inputs and gates are combined into a FlexLogic™ equation. The sequence of entries in the
linear array of parameters follows the general rules listed in the following section.
5.7.4
FlexLogic™ Rules
The general FlexLogic™ rules are listed below.
1.
5–100
Inputs to a gate always precede the gate in the equation.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
2.
Gates have only one output.
3.
The output of a gate can be the input to another gate. Therefore, according to rule 1,
the former gate will precede the latter gate in the equation.
4.
Any input can be used more than once in an equation.
5.
The output of an equation can be used as an input to any equation (including
feedback to itself).
6.
If all parameters of an equation are not used, the ‘END’ parameter must follow the last
parameter used.
As an example, assume that the following logic is required to operate output relay 2:
Percent Diff
OPERATE
Inst Diff
OPERATE
Virtual Output 1
OPERATE
XOR
OR
Output Relay 2
OPERATE
Logic Input 1
ASSERTED
Logic Input 2
ASSERTED
AND
FIGURE 5–47: FlexLogic™ example
Based on the rules given above, the output relay 2 FlexLogic™ equation is shown above.
On the left is a stack of boxes showing the FlexLogic™ messages for output relay 2. On the
right of the stack of boxes is an illustration of how the equation is interpreted.
In this example, the inputs of the four-input OR gate are Percent Diff OP, Inst Diff OP, the
output of the XOR gate, and the output of the AND gate. The inputs of the two-input AND
gate are the output of the NOT gate, and Output Relay 2. The input to the NOT gate is Logic
Input 2. The inputs to the two-input XOR gate are Virtual Output 1 and Logic Input 1. For all
these gates, the inputs precede the gate itself.
This ordering of parameters of an equation, where the gate (or “operator”) follows the input
(or “value”) is commonly referred to as “postfix” or “Reverse Polish” notation.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–101
SETPOINTSCHAPTER 5: SETPOINTS
OUTPUT 2 FLEXLOGIC
O1: Percent Diff OP
OUTPUT 2 FLEXLOGIC
O2: Inst Diff OP
OUTPUT 2 FLEXLOGIC
O3: Virtual Output 1
OUTPUT 2 FLEXLOGIC
O4: Logic Input 1
XOR
OUTPUT 2 FLEXLOGIC
O5: XOR (2 inputs)
OUTPUT 2 FLEXLOGIC
O6: Logic Input 2
OUTPUT 2 FLEXLOGIC
O7: NOT
OUTPUT 2 FLEXLOGIC
O8: Output Relay 2
AND
OUTPUT 2 FLEXLOGIC
O9: AND (2 inputs)
OR
OUTPUT 2 FLEXLOGIC
1O: OR (4 inputs)
OUTPUT 2 FLEXLOGIC
11: END
...
Output Relay 2
OPERATE
OUTPUT 2 FLEXLOGIC
20: END
FIGURE 5–48: FlexLogic™ example implemented
Any equation entered in the 745 that does not make logical sense according to the
notation described here, will be flagged as a self-test error. The SELF TEST ERROR: FlexLogic
Eqn message will be displayed until the error is corrected.
5.7.5
Output Relays
PATH: SETPOINTS ZV S5 OUTPUTS Z OUTPUT RELAYS Z OUTPUT RELAY 1(8)
OUTPUT 1 NAME:
Solid State Trip
Range:
18 alphanumeric characters
MESSAGE
OUTPUT 1 OPERATION:
Self-Resetting
Range:
Self-Resetting, Latched
MESSAGE
OUTPUT 1 TYPE:
Trip
Range:
Trip, Alarm, Control
MESSAGE
OUTPUT 1 FLEXLOGIC
01: Percent Diff Op
Range:
any FlexLogic™ input or gate
Range:
any FlexLogic™ input or gate
„ OUTPUT RELAY 1 [Z]
↓
MESSAGE
OUTPUT 1 FLEXLOGIC
20: END
This section contains the settings (including the FlexLogic™ equation) to configure output
relays 1 to 8.
5–102
•
OUTPUT 1(8) NAME: Press ENTER edit the name of the output. The text may be
changed from “Solid State Trip” one character at a time, using the VALUE keys. Press
ENTER to store the edit and advance to the next character position.
•
OUTPUT 1(8) OPERATION: Select “Latched” to maintain the output 1(8) contacts in the
energized state, even after the condition that caused the contacts to operate is
cleared, until a reset command is issued (or automatically after one week). Select “Selfreset” to automatically de-energize the contacts after the condition is cleared. The
solid state output (output 1) remains closed until externally reset by a momentary
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
interruption of current, unless wired in parallel with an electromechanical relay
(outputs 2 to 8) in which case it turns off when the relay operates.
•
OUTPUT 1(8) TYPE: Select “Trip” to turn the Trip LED on or “Alarm” to turn the Alarm
LED on when this output operates. Otherwise, select “Control”. Note that the Trip LED
remains on until a reset command is issued (or automatically after one week). The
Alarm LED turns off automatically when the output is no longer operated.
•
OUTPUT 1(8) FLEXLOGIC 01 to 20: The twenty (20) messages shown in the table below
are the parameters of the FlexLogic™ equation for output 1(8) as described in the
introduction to FlexLogic™.
The relays can also be energized from individual protection elements.
Note
Table 5–13: Output relay default FlexLogic™
FlexLogic™
gate
Output relay number
1 to 3
4
5
6
7
8
Underfreq 1 OP
Underfreq 2 OP
Freq Decay 3 OP
01
Percent Diff OP
Volts/Hertz 1 OP
W1 THD Level OP
02
Inst Diff OP
Volts/Hertz 2 OP
W2 THD Level OP
03
Any W1 OC OP
OR (2 inputs)
Xfmr Overload OP
04
Any W2 OC OP
END
5th HarmLevel OP
END
END
END
05
OR (4 inputs)
END
OR (4 inputs)
END
END
END
END
END
END
END
END
END
06 to 20
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
Freq Decay R1 OP Freq Decay R2 OP
OR (2 inputs)
OR (2 inputs)
END
END
5–103
SETPOINTSCHAPTER 5: SETPOINTS
FIGURE 5–49: Output relays scheme logic
5–104
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
FIGURE 5–50: Self-test relays scheme logic
5.7.6
Trace Memory
PATH: SETPOINTS ZV S5 OUTPUTS ZV TRACE MEMORY
„ TRACE MEMORY [Z]
MESSAGE
NO. OF PRE-TRIGGER
CYCLES: 12 cycles
Range:
1 to 31 in steps of 1
TRACE TRIG FLEXLOGIC
01: Any Element PKP
Range:
any FlexLogic™ input or gate
Range:
any FlexLogic™ input or gate
↓
MESSAGE
TRACE TRIG FLEXLOGIC
10: END
Trace memory is the oscillography feature of the 745. All system inputs are synchronously
digitized at a sampling rate of 64 times per power cycle. Upon occurrence of a userdefined trigger condition, 32 cycles of oscillography waveforms are captured into trace
memory. The trigger condition is defined by a FlexLogic™ equation, and the number of
pre-trigger cycles of data captured is programmable.
This section contains the settings (including the FlexLogic™ equation) to configure trace
memory triggering.
•
NO. OF PRE-TRIGGER CYCLES: Enter the number of cycles of data, of the 32 cycles of
waveform data to be captured, that are to be pre-trigger information.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–105
SETPOINTSCHAPTER 5: SETPOINTS
•
TRACE TRIG FLEXLOGIC 01 to 10: The following 10 messages are the parameters of
the FlexLogic™ equation for trace memory triggering as described in Introduction to
FlexLogic™ on page 5–99.
The trace memory default FlexLogic™ is as follows: TRACE TRIG FLEXLOGIC 01 is “Any
Element PKP” and TRACE TRIG FLEXLOGIC 02 to 12 are “END”.
5.7.7
Virtual Outputs
PATH: SETPOINTS ZV S5 OUTPUTS ZV TRACE MEMORY
„ VIRTUAL
[Z]
VIRTUAL 1 FLEXLOGIC
01: END
OUTPUT 1
Range:
any FlexLogic™ input or gate
Range:
any FlexLogic™ input or gate
↓
MESSAGE
VIRTUAL 1 FLEXLOGIC
10: END
Virtual outputs are FlexLogic™ equations whose output (or result) can be used as inputs to
other equations. The 745 has five (5) virtual outputs. One application of these outputs may
be to contain a block of logic that is repeated for more than one output.
This section contains the FlexLogic™ equations to configure virtual outputs 1 to 5. The
setpoints describe the parameters of the FlexLogic™ equation for virtual output 1(5) as
described in Introduction to FlexLogic™ on page 5–99.
5.7.8
Timers
PATH: SETPOINTS ZV S5 OUTPUTS ZV TIMERS Z TIMER 1(10)
„ TIMER 1
TIMER 1 START:
END
Range:
any FlexLogic™ input
MESSAGE
TIMER 1 PICKUP
DELAY: 0.00 s
Range:
0.00 to 600.00 s in steps of 0.01
MESSAGE
TIMER 1 DROPOUT
DELAY: 0.00 s
Range:
0.00 to 600.00 s in steps of 0.01
[Z]
Protection and monitoring elements already have their own programmable delay timers,
where they are required. For additional flexibility, ten (10) independent timers are available
for implementing custom schemes where timers are not available. For example, a pickup
delay timer may be required on a logic input; or, a single delay timer may be required on
the output of a block of logic.
5–106
•
TIMER 1(10) START: Select the FlexLogic™ entry which, when operated or asserted, will
start timer 1(10).
•
TIMER 1(10) PICKUP DELAY: Enter the delay time during which the start condition for
timer 1(10) must remain operated or asserted, before the timer will operate.
•
TIMER 1(10) DROPOUT DELAY: Enter the delay time after which the start condition for
timer 1(10) must remain not operated or not asserted, before the timer will stop
operating.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
5.8
S6 Testing
5.8.1
Description
The 745 provides various diagnostic tools to verify the relay functionality. The normal
function of all output contacts can be overridden and forced to be energized or deenergized. Analog outputs may be forced to any level of their output range. The simulation
feature allows system parameters (magnitudes and angles) to be entered as setpoints and
made to generate fault conditions without the necessity of any system connections. In
addition, 32 cycles of sampled current/voltage waveform data (in IEEE COMTRADE file
format) can be loaded and “played back” to test the response of the 745 under any
(previously recorded) system disturbance.
5.8.2
Output Relays
PATH: SETPOINTS ZV S6 TESTING Z OUTPUT RELAYS
„ OUTPUT RELAYS [Z]
MESSAGE
FORCE OUTPUT RELAYS
FUNCTION: Disabled
Range:
Enabled, Disabled
FORCE OUTPUT 1:
De-Energized
Range:
De-energized, Energized
↓
MESSAGE
FORCE OUTPUT 8:
De-energized
Range:
De-energized, Energized
MESSAGE
FORCE SELF-TEST RLY:
De-energized
Range:
De-energized, Energized
The 745 has the ability to override the normal function of all outputs, forcing each to
energize and de-energize for testing. Enabling this feature turns the In Service LED off and
the Test Mode LED on. Refer to FIGURE 5–49: Output relays scheme logic on page 5–104 for
the output relay scheme logic.
•
FORCE OUTPUT RELAYS FUNCTION: Select “Enabled” to enable the output relay
testing feature and override normal output relay operation. This setpoint is defaulted
to “Disabled” at power on.
•
FORCE OUTPUT 1 to 8: Select “Energized” to force output 1(8) to the energized state or
“De-energized” to force output 1(8) to the de-energized state. This setpoint is only
operational when output relay testing is enabled.
•
FORCE SELF-TEST RLY: Select “Energized” to force the self-test relay to the energized
state and “De-energized” to force to the de-energized state. This setpoint is only
operational while the output relay testing feature is enabled.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–107
SETPOINTSCHAPTER 5: SETPOINTS
5.8.3
Analog Outputs
PATH: SETPOINTS ZV S6 TESTING ZV ANALOG OUTPUTS
„ ANALOG OUTPUTS [Z]
MESSAGE
FORCE ANALOG OUTPUTS
FUNCTION: Disabled
Range:
Enabled, Disabled
FORCE ANALOG OUT 1:
0%
Range:
0 to 100% in steps of 1
Range:
0 to 100% in steps of 1
↓
MESSAGE
FORCE ANALOG OUT 7:
0%
The 745 has the ability to override the normal function of analog transducer outputs,
forcing each to any level of its output range. Enabling this feature turns the Test Mode LED
on and de-energize the self-test relay.
5.8.4
•
FORCE ANALOG OUTPUT FUNCTION: Select “Enabled” to enable the analog output
testing and override the analog output normal operation. This setpoint defaults to
“Disabled” at power on.
•
FORCE ANALOG OUT 1(7): Enter the percentage of the DC mA output range of analog
output 1(7). For example, if the analog output range has been programmed to 4 to 20
mA, entering 100% outputs 20 mA, 0% outputs 4 mA, and 50% outputs 12 mA. This
setpoint is only operational if analog output testing is enabled.
Simulation
5.8.4.1 Main Menu
PATH: SETPOINTS ZV S4 ELEMENTS ZV INSULATION AGING
„ SIMULATION
[ Z]
„ SIMULATION
[ Z]
SETUP
MESSAGE
MESSAGE
„ PREFAULT
[ Z]
VALUES
„ FAULT VALUES [Z]
See below.
See page 5–110
See page 5–110
5.8.4.2 Simulation Setup
PATH: SETPOINTS ZV S6 TESTING ZV SIMULATION Z SIMULATION SETUP
„ SIMULATION
SIMULATION FUNCTION:
Disabled
Range:
Disabled, Prefault Mode, Fault
Mode, Playback Mode
MESSAGE
BLOCK OPERATION OF
OUTPUTS: 12345678
Range:
Any combination of outputs 1
to 8
MESSAGE
START FAULT MODE
SIGNAL: Disabled
Range:
Disabled, Logc Inpt 1 to 16
MESSAGE
START PLAYBACK MODE
SIGNAL: Disabled
Range:
Disabled, Logc Inpt 1 to 16
[Z]
SETUP
The simulation feature allows testing of the functionality of the relay in response to
programmed conditions, without the need of external AC voltage and current inputs.
System parameters such as currents and voltages, phase angles and system frequency
5–108
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
are entered as setpoints. When placed in simulation mode, the relay suspends reading
actual AC inputs and generates samples to represent the programmed phasors. These
samples are used in all calculations and protection logic. Enabling this feature will turn off
the In Service LED, turn on the Test Mode LED, and de-energize the self-test relay.
When in simulation mode, protection features do not operate based on actual system
inputs. If simulation mode is used for field testing on equipment, other means of
protection must be provided by the operator.
•
SIMULATION FUNCTION: Select the simulation mode required. Select “Disabled” to
return the 745 to normal operation. The following table details the simulation function
modes.
–
“Prefault Mode”: Select prefault mode to simulate the normal operating condition
of a transformer. In this mode, the normal inputs are replaced with sample values
generated based on the programmed prefault values. Phase currents are
balanced (i.e. equal in magnitude and 120° apart), and the phase lag between
windings is that which would result under normal conditions for the transformer
type selected. The magnitude of phase currents for each winding are set to the
values programmed in S6 TESTING ZV SIMULATION ZV PREFAULT VALUES ZV
W1(3) PHASE ABC CURRENT MAGNITUDE. The magnitude of the voltage is set to
the value programmed in S6 TESTING ZV SIMULATION ZV PREFAULT VALUES ZV
VOLTAGE INPUT MAGNITUDE. The frequency is set to the value programmed in S2
SYSTEM SETUP Z TRANSFORMER Z NOMINAL FREQUENCY.
–
“Fault Mode”: Select fault mode to simulate the faulted operating condition of a
transformer. In this mode, the normal inputs are replaced with sample values
generated based on the programmed fault values. The magnitude and angle of
each phase current and ground current of the available windings, the magnitude
and angle of the voltage input, and system frequency are set to the values
programmed under S6 TESTING ZV SIMULATION ZV FAULT VALUES.
A logic input, programmed to the “Simulate Fault” function, can be used to trigger the
transition from the “Prefault Mode” to the “Fault Mode”, allowing the measurement of
element operating times.
–
“Playback Mode”: Select playback mode to play back a sampled waveform data
file which has been pre-loaded into the relay. In this mode, the normal inputs are
replaced with 32 cycles of waveform samples downloaded into the 745 by the
EnerVista 745 Setup software (from an oscillography data file in the IEEE
COMTRADE file format).
A logic input, programmed to the “Simulate Playback” function, can be used to trigger
the transition from the “Prefault Mode” to the “Playback Mode”, allowing the
measurement of element operating times.
•
BLOCK OPERATION OF OUTPUTS: Select the output relays which must be blocked
from operating while in simulation mode. An operator can use the simulation feature
to provide a complete functional test of the protection features, except for the
measurement of external input values. As this feature may be used for on site testing,
provision is made (with this setpoint) to block the operation of output relays during this
testing, to prevent the operation of other equipment. Note that the default setting
blocks the operation of all output relays.
•
START FAULT MODE SIGNAL: Select any logic input which, when asserted, initiates
fault mode simulation. This signal has an effect only if the 745 is initially in prefault
mode.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–109
SETPOINTSCHAPTER 5: SETPOINTS
•
START PLAYBACK MODE SIGNAL: Select any logic input which, when asserted, initiates
playback mode simulation. This signal has an effect only if the 745 is initially in prefault
mode.
5.8.4.3 Prefault Values
PATH: SETPOINTS ZV S6 TESTING ZV SIMULATION ZV PREFAULT VALUES
„ PREFAULT
W1 PHASE ABC CURRENT
MAGNITUDE: 1.0 x CT
Range:
0.0 to 40.0 x CT in steps of 0.1
MESSAGE
W2 PHASE ABC CURRENT
MAGNITUDE: 1.0 x CT
Range:
0.0 to 40.0 x CT in steps of 0.1
MESSAGE
W3 PHASE ABC CURRENT
MAGNITUDE: 1.0 x CT
Range:
0.0 to 40.0 x CT in steps of 0.1
MESSAGE
VOLTAGE INPUT
MAGNITUDE: 1.0 x VT
Range:
0.0 to 2.0 x VT in steps of 0.1
[ Z]
VALUES
•
W1 to W3 PHASE ABC CURRENT MAGNITUDE: Enter the winding 1(3) phase current
magnitude (in terms of the winding full load current) while in prefault mode.
•
VOLTAGE INPUT MAGNITUDE: Enter the voltage magnitude (in terms of the nominal
VT secondary voltage) while in prefault mode.
5.8.4.4 Fault Values
PATH: SETPOINTS ZV S6 TESTING ZV SIMULATION ZV FAULT VALUES
„ FAULT
W1 PHASE A CURRENT
MAGNITUDE: 1.0 x CT
Range:
0.0 to 40.0 x CT in steps of 0.1
MESSAGE
W1 PHASE A CURRENT
ANGLE: 0°
Range:
0 to 359° in steps of 1
MESSAGE
W1 PHASE B CURRENT
MAGNITUDE: 1.0 x CT
Range:
0.0 to 40.0 x CT in steps of 0.1
MESSAGE
W1 PHASE B CURRENT
ANGLE: 0°
Range:
0 to 359° in steps of 1
MESSAGE
W1 PHASE C CURRENT
MAGNITUDE: 1.0 x CT
Range:
0.0 to 40.0 x CT in steps of 0.1
MESSAGE
W1 PHASE C CURRENT
ANGLE: 0°
Range:
0 to 359° in steps of 1
MESSAGE
W1 GROUND CURRENT
MAGNITUDE: 0.0 x CT
Range:
0.0 to 40.0 x CT in steps of 0.1
MESSAGE
W1 GROUND CURRENT
ANGLE: 0°
Range:
0 to 359° in steps of 1
MESSAGE
W2 PHASE A CURRENT
MAGNITUDE: 1.0 x CT
Range:
0.0 to 40.0 x CT in steps of 0.1
MESSAGE
W2 PHASE A CURRENT
ANGLE: 0°
Range:
0 to 359° in steps of 1
MESSAGE
W2 PHASE B CURRENT
MAGNITUDE: 1.0 x CT
Range:
0.0 to 40.0 x CT in steps of 0.1
MESSAGE
W2 PHASE B CURRENT
ANGLE: 0°
Range:
0 to 359° in steps of 1
[ Z]
VALUES
5–110
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTSSETPOINTS
MESSAGE
W2 PHASE C CURRENT
MAGNITUDE: 1.0 x CT
Range:
0.0 to 40.0 x CT in steps of 0.1
MESSAGE
W2 PHASE C CURRENT
ANGLE: 0°
Range:
0 to 359° in steps of 1
MESSAGE
W2 GROUND CURRENT
MAGNITUDE: 0.0 x CT
Range:
0.0 to 40.0 x CT in steps of 0.1
MESSAGE
W2 GROUND CURRENT
ANGLE: 0°
Range:
0 to 359° in steps of 1
MESSAGE
W3 PHASE A CURRENT
MAGNITUDE: 1.0 x CT
Range:
0.0 to 40.0 x CT in steps of 0.1
MESSAGE
W3 PHASE A CURRENT
ANGLE: 0°
Range:
0 to 359° in steps of 1
MESSAGE
W3 PHASE B CURRENT
MAGNITUDE: 1.0 x CT
Range:
0.0 to 40.0 x CT in steps of 0.1
MESSAGE
W3 PHASE B CURRENT
ANGLE: 0°
Range:
0 to 359° in steps of 1
MESSAGE
W3 PHASE C CURRENT
MAGNITUDE: 1.0 x CT
Range:
0.0 to 40.0 x CT in steps of 0.1
MESSAGE
W3 PHASE C CURRENT
ANGLE: 0°
Range:
0 to 359° in steps of 1
MESSAGE
W3 GROUND CURRENT
MAGNITUDE: 0.0 x CT
Range:
0.0 to 40.0 x CT in steps of 0.1
MESSAGE
W3 GROUND CURRENT
ANGLE: 0°
Range:
0 to 359° in steps of 1
MESSAGE
VOLTAGE INPUT
MAGNITUDE: 1.0 x VT
Range:
0.0 to 2.0 x VT in steps of 0.1
MESSAGE
VOLTAGE INPUT
ANGLE: 0° Lag
Range:
0 to 359° Lag in steps of 1
MESSAGE
FREQUENCY:
60.00 Hz
Range:
45.00 to 60.00 Hz in steps of
0.01
•
W1(W3) PHASE A(C) CURRENT MAGNITUDE: Enter the winding 1(3) phase A(C) current
magnitude (in terms of the winding full load current) while in fault mode.
•
W1(3) PHASE A(C) CURRENT ANGLE: Enter the winding 1(3) phase A(C) current angle
(with respect to the winding 1 phase A current phasor) while in fault mode. Note that
the winding 1 phase A current angle cannot be edited and is used as a reference for
the other phase angles.
•
W1(3) GROUND CURRENT MAGNITUDE: Enter the winding 1(3) ground current
magnitude (in terms of the winding FLC) while in fault mode. Note that ground refers
to the measured CT current in the connection between transformer neutral and
ground. As such, this message only appears for wye or zig-zag connected windings.
•
W1(3) GROUND CURRENT ANGLE: Enter the winding 1(3) ground current angle (with
respect to the winding 1 phase A current phasor). This message only appears for wye
or zig-zag connected windings.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
5–111
SETPOINTSCHAPTER 5: SETPOINTS
5.8.5
Factory Service
PATH: SETPOINTS ZV S6 TESTING ZV SIMULATION ZV FACTORY SERVICE
„ FACTORY SERVICE [Z]
ENTER FACTORY
PASSCODE:
Range:
Restricted access for factory
personnel only
This section contains settings intended for factory use only, for calibration, testing, and
diagnostics. The messages can only be accessed by entering a factory service passcode in
the first message.
5–112
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
GE Consumer & Industrial
Multilin
745 Transformer Protection
System
Chapter 6: Actual values
Actual values
6.1
Overview
6.1.1
Message Map
Measured values, event records and product information are actual values. Actual values
may be accessed via any of the following methods:
•
Front panel, using the keys and display.
•
Front program port or rear Ethernet port and a portable computer running the
EnerVista 745 Setup software supplied with the relay.
•
Rear RS485/RS422 COM 1 port or RS485 COM 2 port with any system running user
written software.
Any of these methods can be used to view the same information. A computer, however,
makes viewing much more convenient, since more than one piece of information can be
viewed at the same time.
„ ACTUAL VALUES [Z]
„ NETWORK STATUS [Z]
A1 STATUS
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
„ DATE AND TIME [Z]
„ LOGIC INPUTS [Z]
„ VIRTUAL INPUTS [Z]
„ OUTPUT RELAYS [Z]
„ VIRTUAL
OUTPUTS
[ Z]
See page 6–4
See page 6–4
See page 6–5
See page 6–5
See page 6–5
See page 6–6
6–1
ACTUAL VALUESCHAPTER 6: ACTUAL VALUES
MESSAGE
MESSAGE
„ ACTUAL VALUES [Z]
„ SELF-TEST
[Z]
ERRORS
„ END OF PAGE A1
„ CURRENT
[ Z]
A2 METERING
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
„ ACTUAL VALUES [Z]
„ HARMONIC
[ Z]
CONTENT
„ FREQUENCY
[ Z]
„ TAP CHANGER
„ VOLTAGE
[ Z]
„ DEMAND
[Z]
„ AMBIENT
[ Z]
TEMPERATURE
„ LOSS OF LIFE [Z]
„ ANALOG INPUT [Z]
„ POWER
[ Z]
„ ENERGY
[ Z]
[ Z]
CLEAR
MESSAGE
See page 6–10
See page 6–12
See page 6–12
See page 6–12
See page 6–13
See page 6–14
See page 6–14
See page 6–15
See page 6–15
See page 6–15
„ END OF PAGE A2
„ EVENT DATA
A3 EVENT RECORDER
[ Z]
See page 6–7
„ EVENT 256
[ Z]
See page 6–17
See page 6–17
↓
MESSAGE
MESSAGE
„ ACTUAL VALUES [Z]
[Z]
[Z]
SUPPORT
MESSAGE
See page 6–17
„ END OF PAGE A3
„ TECHNICAL
A4 PRODUCT INFO
6–2
„ EVENT 1
„ REVISION CODES [Z]
See page 6–21
See page 6–21
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 6: ACTUAL VALUESACTUAL VALUES
MESSAGE
MESSAGE
6.1.2
„ CALIBRATION
[Z]
See page 6–22
„ END OF PAGE A4
Description
Actual value messages are organized into logical groups, or pages, for easy reference. All
actual value messages are illustrated and described in blocks throughout this chapter. A
reference of all messages is also provided at the end of the chapter. All values shown in
these message illustrations assume that no inputs (besides control power) are connected
to the 745.
Some messages appear on the following pages with a gray background. This indicates
that the message may not appear depending upon the configuration of the relay (as
selected by setpoints) or the options installed in the relay during manufacture. For
example, no display associated with winding 3 will ever appear if the relay is not
configured for three-winding operation.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
6–3
ACTUAL VALUESCHAPTER 6: ACTUAL VALUES
6.2
A1 Status
6.2.1
Network Status
PATH: ACTUAL VALUES Z A1 STATUS Z NETWORK STATUS
„ NETWORK STATUS [Z]
MESSAGE
Ethernet Lnk Con Dia
Status [„] [„] [„]
Range:
see description
below
MAC ADDRESS:
00:20:32:F8:7F
Range:
MAC address,
example shown
These actual values appear when the relay is ordered with the Ethernet (T) option.
The ETHERNET STATUS actual value message indicates the status of the Ethernet link,
connection, and diagnostic via three indicators. The [„] symbol indicates on, and the [ ]
symbol indicates off. There is also a blinking indication.
The box under Lnk column indicates the Ethernet link status. If it is on, the Ethernet port is
connected to the network; if it is off, the port is disconnected. This indicator is normally on.
The box under the Con column indicates the connection status. If on, the Ethernet port is
configured and ready to transmit and receive data. If blinking, the Ethernet port is either
active (transmitting or receiving data) or indicating an error if the diagnostic status is also
on or blinking.
The box under the Dia column indicates the diagnostic status. If it is on, then either a fatal
Ethernet port error has occurred or there is a duplicate IP address on the network. If
blinking, then there is a non-fatal network error. Off indicates no errors.
6.2.2
Date and Time
PATH: ACTUAL VALUES Z A1 STATUS ZV DATE AND TIME
„ DATE AND TIME [Z]
CURRENT DATE:
Jan 01 2001
MESSAGE
CURRENT TIME:
00:00:00
The current date and time are displayed here.
6.2.3
Logic Inputs
PATH: ACTUAL VALUES Z A1 STATUS ZV LOGIC INPUTS
„ LOGIC INPUTS [Z]
LOGIC INPUT 1
STATE: Not Asserted
MESSAGE
LOGIC INPUT 2
STATE: Not Asserted
↓
6–4
MESSAGE
LOGIC INPUT 16
STATE: Not Asserted
MESSAGE
SETPOINT ACCESS
STATE: Open
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 6: ACTUAL VALUESACTUAL VALUES
The states of logic inputs 1 through 16 and the setpoint access jumper are displayed here.
Setpoints cannot be changed from the front panel when the SETPOINT ACCESS STATE is
“Open”.
6.2.4
Virtual Inputs
PATH: ACTUAL VALUES Z A1 STATUS ZV VIRTUAL INPUTS
„ VIRTUAL INPUTS [Z]
VIRTUAL INPUT 1
STATE: Not Asserted
MESSAGE
VIRTUAL INPUT 2
STATE: Not Asserted
↓
MESSAGE
VIRTUAL INPUT 16
STATE: Not Asserted
The states of virtual inputs 1 through 16 are displayed here.
6.2.5
Output Relays
PATH: ACTUAL VALUES Z A1 STATUS ZV OUTPUT RELAYS
„ OUTPUT RELAYS [Z]
OUTPUT RELAY 1
STATE: De-energized
MESSAGE
OUTPUT RELAY 2
STATE: De-energized
↓
MESSAGE
OUTPUT RELAY 8
STATE: De-energized
MESSAGE
SELF-TEST RELAY
STATE: Energized
The states of output relays 1 through 8 and the self-test relay are displayed here.
6.2.6
Virtual Outputs
PATH: ACTUAL VALUES Z A1 STATUS ZV VIRTUAL OUTPUTS
„ VIRTUAL OUTPUTS [Z]
VIRTUAL OUTPUT 1
STATE: Not Asserted
MESSAGE
VIRTUAL OUTPUT 2
STATE: Not Asserted
↓
MESSAGE
VIRTUAL OUTPUT 5
STATE: Not Asserted
The states of virtual outputs 1 through 5 are displayed here.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
6–5
ACTUAL VALUESCHAPTER 6: ACTUAL VALUES
6.2.7
Self-test Errors
PATH: ACTUAL VALUES Z A1 STATUS ZV SELF-TEST ERRORS
„ SELF-TEST
[Z]
FLEXLOGIC EQN ERROR:
None
ERRORS
MESSAGE
BAD SETTINGS ERROR:
None
The FLEXLOGIC EQN ERROR value displays the source of the error occurring in a
FlexLogic™ equation. The BAD SETTINGS ERROR value displays the cause of a bad setting
made while assigning setpoint values.
6–6
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 6: ACTUAL VALUESACTUAL VALUES
6.3
A2 Metering
6.3.1
Current
6.3.1.1 Main Menu
PATH: ACTUAL VALUES ZV A2 METERING Z CURRENT
„ CURRENT
[ Z]
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
„ W1 CURRENT
[ Z]
„ W2 CURRENT
[ Z]
„ W3 CURRENT
[ Z]
„ POSITIVE
[ Z]
SEQUENCE
„ NEGATIVE
[ Z]
SEQUENCE
„ ZERO SEQUENCE [Z]
„ DIFFERENTIAL [Z]
„ RESTRAINT
„ GROUND
[ Z]
[ Z]
DIFFERENTIAL
See below.
See below.
See below.
See page 6–8
See page 6–8
See page 6–9
See page 6–9
See page 6–9
See page 6–10
For each monitored winding, the fundamental frequency magnitude and phase angle of
phase A, B, C and ground currents are recalculated every half-cycle for use in differential
and overcurrent protection. From these values, neutral, positive, negative and zerosequence as well as differential, restraint and ground differential currents are calculated.
These are displayed and updated approximately twice a second for readability.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
6–7
ACTUAL VALUESCHAPTER 6: ACTUAL VALUES
6.3.1.2 Winding Currents
PATH: ACTUAL VALUES ZV A2 METERING Z CURRENT Z W1(3) CURRENT
„ W1 CURRENT
[ Z]
W1 PHASE A CURRENT:
0 A at 0° Lag
MESSAGE
W1 PHASE B CURRENT:
0 A at 0° Lag
MESSAGE
W1 PHASE C CURRENT:
0 A at 0° Lag
MESSAGE
W1 NEUTRAL CURRENT:
0 A at 0° Lag
MESSAGE
W1 GROUND CURRENT:
0 A at 0° Lag
MESSAGE
WINDING 1 LOADING:
0% of rated load
MESSAGE
W1 AVERAGE PHASE
CURRENT: 0 A
The fundamental frequency current magnitudes for winding 1 phases A, B, and C, neutral,
and ground are shown. The current angle for phase A is always set to 0° as it is used as
reference for all other currents, both measured and derived. The maximum specified load
and average phase current are also shown for the specified winding.
6.3.1.3 Positive-sequence Current
PATH: ACTUAL VALUES ZV A2 METERING Z CURRENT ZV POSITIVE SEQUENCE
[Z]
„ POSITIVE
SEQUENCE
Note
W1 POS SEQ CURRENT:
0 A at 0° Lag
MESSAGE
W2 POS SEQ CURRENT:
0 A at 0° Lag
MESSAGE
W3 POS SEQ CURRENT:
0 A at 0° Lag
All positive-, negative-, and zero- sequence component phase angles are referenced to
the winding 1 phase A current
The positive-sequence current magnitudes and phase values for windings 1, 2, and 3 are
shown here.
6.3.1.4 Negative-sequence Current
PATH: ACTUAL VALUES ZV A2 METERING Z CURRENT ZV NEGATIVE SEQUENCE
„ NEGATIVE
SEQUENCE
6–8
[Z]
W1 NEG SEQ CURRENT:
0 A at 0° Lag
MESSAGE
W2 NEG SEQ CURRENT:
0 A at 0° Lag
MESSAGE
W3 NEG SEQ CURRENT:
0 A at 0° Lag
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 6: ACTUAL VALUESACTUAL VALUES
The negative-sequence current magnitudes and phase values for windings 1, 2, and 3 are
shown here.
6.3.1.5 Zero-sequence Current
PATH: ACTUAL VALUES ZV A2 METERING Z CURRENT ZV ZERO SEQUENCE
„ ZERO SEQUENCE [Z]
W1 ZERO SEQ CURRENT:
0 A at 0° Lag
MESSAGE
W2 ZERO SEQ CURRENT:
0 A at 0° Lag
MESSAGE
W3 ZERO SEQ CURRENT:
0 A at 0° Lag
The zero-sequence current magnitudes and phase values for windings 1, 2, and 3 are
shown here.
6.3.1.6 Differential Current
PATH: ACTUAL VALUES ZV A2 METERING Z CURRENT ZV DIFFERENTIAL
„ DIFFERENTIAL
[Z]
PHASE A DIFFERENTIAL
CURRENT: 0.00 x CT
MESSAGE
PHASE A DIFFERENTIAL
ANGLE: 0° Lag
MESSAGE
PHASE B DIFFERENTIAL
CURRENT: 0.00 x CT
MESSAGE
PHASE B DIFFERENTIAL
ANGLE: 0° Lag
MESSAGE
PHASE C DIFFERENTIAL
CURRENT: 0.00 x CT
MESSAGE
PHASE C DIFFERENTIAL
ANGLE: 0° Lag
The differential current magnitudes and angles for phases A, B, and C are shown. The
differential current phase angles are referenced to winding 1 phase A current.
6.3.1.7 Restraint Current
PATH: ACTUAL VALUES ZV A2 METERING Z CURRENT ZV RESTRAINT
„ RESTRAINT
[ Z]
PHASE A RESTRAINT
CURRENT: 0.00 x CT
MESSAGE
PHASE B RESTRAINT
CURRENT: 0.00 x CT
MESSAGE
PHASE C RESTRAINT
CURRENT: 0.00 x CT
The restraint current magnitudes for phases A, B, and C are shown here.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
6–9
ACTUAL VALUESCHAPTER 6: ACTUAL VALUES
6.3.1.8 Ground Differential Current
PATH: ACTUAL VALUES ZV A2 METERING Z CURRENT ZV GROUND DIFFERENTIAL
„ GROUND
[ Z]
DIFFERENTIAL
W1 GND DIFFERENTIAL
CURRENT: 0.00 x CT
MESSAGE
W2 GND DIFFERENTIAL
CURRENT: 0.00 x CT
MESSAGE
W3 GND DIFFERENTIAL
CURRENT: 0.00 x CT
The ground differential current magnitudes for windings 1 through 3 are shown.
6.3.2
Harmonic Content
6.3.2.1 Main Menu
PATH: ACTUAL VALUES ZV A2 METERING ZV HARMONIC CONTENT
„ HARMONIC
CONTENT
„ 2nd HARMONIC [Z]
[ Z]
See page 6–10
↓
MESSAGE
MESSAGE
MESSAGE
„ 21st HARMONIC [Z]
„ THD
[ Z]
„ HARMONIC
DERATING
See page 6–10
See page 6–11
[ Z]
See page 6–11
The 745 can determine the harmonic components of every current that it measures. This
allows it to calculate total harmonic distortion (THD) as well as a harmonic derating factor
that can be used to adjust phase time overcurrent protection to account for additional
internal energy dissipation that arises from the presence of harmonic currents.
6.3.2.2 Harmonic Sub-components
PATH: ACTUAL VALUES ZV A2 METERING ZV HARMONIC... Z 2nd(21st) HARMONIC
„ 2nd HARMONIC [Z]
W1 (% f0) H2a: 0.0
H2b: 0.0 H2c: 0.0
MESSAGE
W2 (% f0) H2a: 0.0
H2b: 0.0 H2c: 0.0
MESSAGE
W3 (% f0) H2a: 0.0
H2b: 0.0 H2c: 0.0
The 745 is capable of measuring harmonic components up to a frequency of 21 times
nominal system frequency. An actual value is calculated for each phase of each monitored
winding. The example above shows what is displayed in a typical case for harmonic
components (in this case the second harmonic). Similar displays exist for all harmonics up
to the 21st .
6–10
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 6: ACTUAL VALUESACTUAL VALUES
The second harmonic magnitude for each phase current of windings 1 through 3 are
displayed. Values are expressed as a percentage of magnitude of the corresponding
fundamental frequency component.
6.3.2.3 Total Harmonic Distortion (THD)
PATH: ACTUAL VALUES ZV A2 METERING ZV HARMONIC CONTENT ZV THD
„ THD
[Z]
W1 THDa (2nd-21st):
0.0% ƒo
MESSAGE
W1 THDb (2nd-21st):
0.0% ƒo
MESSAGE
W1 THDc (2nd-21st):
0.0% ƒo
MESSAGE
W2 THDa (2nd-21st):
0.0% ƒo
MESSAGE
W2 THDb (2nd-21st):
0.0% ƒo
MESSAGE
W2 THDc (2nd-21st):
0.0% ƒo
MESSAGE
W3 THDa (2nd-21st):
0.0% ƒo
MESSAGE
W3 THDb (2nd-21st):
0.0% ƒo
MESSAGE
W3 THDc (2nd-21st):
0.0% ƒo
THD is calculated and displayed. Every THD value is calculated as the ratio of the RMS
value of the sum of the squared individual harmonic amplitudes to the RMS value of the
fundamental frequency. The calculations are based on IEEE standard 519-1986.
The actual values messages display the total harmonic distortion for phase A, B, and C
currents for windings 1 through 3, expressed as a percentage of the fundamental
frequency component. The numbers in parentheses indicate the programmed frequency
band (in terms of harmonic number) over which THD is being calculated.
6.3.2.4 Harmonic Derating Factor
PATH: ACTUAL VALUES ZV A2 METERING ZV HARMONIC... ZV HARMONIC DERATING
„ HARMONIC
DERATING
Note
[ Z]
W1 HARMONIC DERATING
FACTOR: 1.00
MESSAGE
W2 HARMONIC DERATING
FACTOR: 1.00
MESSAGE
W3 HARMONIC DERATING
FACTOR: 1.00
These actual values are shown only if the harmonic derating function is enabled.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
6–11
ACTUAL VALUESCHAPTER 6: ACTUAL VALUES
The harmonic derating factor for each of the windings shows the effect of non-sinusoidal
load currents on power transformer’s rated full load current. The calculations are based on
ANSI/IEEE standard C57.110-1986. The actual values messages display the harmonic
derating factor for windings 1 through 3.
6.3.3
Frequency
PATH: ACTUAL VALUES ZV A2 METERING ZV FREQUENCY
[ Z]
„ FREQUENCY
SYSTEM FREQUENCY:
0.00 Hz
MESSAGE
FREQUENCY DECAY
RATE: 0.00 Hz/s
The SYSTEM FREQUENCY is calculated from the voltage input provided that voltage
sensing is enabled and the injected voltage is above 50% of VT. If these criteria are not
satisfied, then it is determined from winding 1 phase A current provided that it is above
0.05 × CT. If frequency still cannot be calculated, “0.00 Hz” is displayed, though the
sampling rate is then set for the S2 SYSTEM SETUP Z TRANSFORMER Z NOMINAL
FREQUENCY setpoint. The FREQUENCY DECAY RATE can only be calculated if system
frequency can be calculated.
6.3.4
Tap Changer
PATH: ACTUAL VALUES Z A2 METERING ZV TAP CHANGER
„ TAP CHANGER
[ Z]
TAP CHANGER
POSITION: n/a
This message displays the actual tap position. If tap position sensing is disabled, “n/a” will
be displayed.
6.3.5
Voltage
PATH: ACTUAL VALUES ZV A2 METERING ZV VOLTAGE
„ VOLTAGE
[ Z]
SYSTEM LINE-TO-LINE
VOLTAGE: 0.00 kV
MESSAGE
VOLTS-PER-HERTZ:
0.00 V/Hz
MESSAGE
LINE-NTRL VOLTAGE:
0.00 kV at 0° Lag
For phase-to-neutral input voltages, the SYSTEM LINE-TO-LINE VOLTAGE displays its lineto-line equivalent.
6–12
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 6: ACTUAL VALUESACTUAL VALUES
6.3.6
Demand
6.3.6.1 Main Menu
PATH: ACTUAL VALUES ZV A2 METERING ZV DEMAND
„ DEMAND
„ DEMAND DATA
[ Z]
[ Z]
CLEAR
MESSAGE
MESSAGE
MESSAGE
„ W1 CURRENT
[ Z]
DEMAND
„ W2 CURRENT
[ Z]
DEMAND
„ W3 CURRENT
[ Z]
DEMAND
See page 6–13
See page 6–14
See page 6–14
See page 6–14
Current demand is measured on each phase of each monitored winding. These
parameters can be monitored to reduce supplier demand penalties or for statistical
metering purposes. The calculated demand is based on the S2 SYSTEM SETUP ZV DEMAND
METERING Z CURRENT DEMAND METER TYPE setpoint value. For each quantity, the 745
displays the demand over the most recent demand time interval, the maximum demand
since the last date that the demand data was reset, and the time and date stamp of this
maximum value.
6.3.6.2 Demand Data Clear
PATH: ACTUAL VALUES ZV A2 METERING ZV DEMAND Z DEMAND DATA CLEAR
„ DEMAND DATA
CLEAR
[Z]
CLEAR MAX DEMAND
DATA: No
MESSAGE
DATE OF LAST CLEAR:
Jan 01 1996
MESSAGE
TIME OF LAST CLEAR:
00:00:00.000
To clear all maximum demand data, set CLEAR MAX DEMAND DATA to “Yes”. The last time
that the demand data were cleared is also displayed. If the date has never been
programmed, the default values shown above appear.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
6–13
ACTUAL VALUESCHAPTER 6: ACTUAL VALUES
6.3.6.3 Current Demand
PATH: ACTUAL VALUES ZV A2 METERING ZV DEMAND ZV W1(3) CURRENT DEMAND
„ W1 CURRENT
DEMAND
[ Z]
W1 PHASE A CURRENT
DEMAND: 0 A
MESSAGE
W1 PHASE B CURRENT
DEMAND: 0 A
MESSAGE
W1 PHASE C CURRENT
DEMAND: 0 A
MESSAGE
MAXIMUM W1 DEMAND:
0 A in phase A
MESSAGE
MAXIMUM W1 DEMAND
DATE: Jan 01 1996
MESSAGE
MAXIMUM W1 DEMAND
TIME: 00:00:00.000
The current demand for winding 1 phases A through C are displayed in these messages.
The maximum current demand, the phase in which it occurred, and the date and time it
occurred are also shown. If the date has never been programmed, the default values
shown above appear. These messages are repeated for windings 2 and 3.
6.3.7
Ambient Temperature
PATH: ACTUAL VALUES ZV A2 METERING ZV AMBIENT TEMPERATURE
„ AMBIENT
[Z]
TEMPERATURE
AMBIENT TEMPERATURE:
0°C
Ambient temperature is monitored via an RTD connected to the 745.
6.3.8
Loss of Life
PATH: ACTUAL VALUES ZV A2 METERING ZV LOSS OF LIFE
„ LOSS OF LIFE
[Z]
HOTTEST-SPOT WINDING
TEMPERATURE: 1°C
MESSAGE
INSULATION AGING
FACTOR:
0.0
MESSAGE
TOTAL ACCUM LOSS OF
LIFE: 0.00 hours
The HOTTEST-SPOT WINDING TEMPERATURE is calculated from the ambient temperature
and the highest-load winding current. The INSULATION AGING FACTOR is calculated from
the hottest-spot temperature. The TOTAL ACCUM LOSS OF LIFE value displays the total
equivalent service hours of the transformer.
6–14
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 6: ACTUAL VALUESACTUAL VALUES
6.3.9
Analog Input
PATH: ACTUAL VALUES Z A2 METERING ZV ANALOG INPUT
„ ANALOG INPUT [Z]
ANALOG INPUT:
0 μA
The 745 provides the ability to monitor any external quantity via an auxiliary current input
called the Analog Input. The scaled value of the analog input is shown. In this message, the
name programmed in S2 SYSTEM SETUP ZV ANALOG INPUT Z ANALOG INPUT NAME is
displayed instead of ANALOG INPUT (the factory default), and the units programmed in S2
SYSTEM SETUP ZV ANALOG INPUT ZV ANALOG INPUT UNITS are displayed instead of “µA”
(which is the factory default).
6.3.10 Power
PATH: ACTUAL VALUES ZV A2 METERING ZV POWER w W1(3) POWER
„ W1 POWER
[ Z]
W1 REAL POWER:
0 MW
MESSAGE
W1 REACTIVE POWER:
0 Mvar
MESSAGE
W1 APPARENT POWER:
0 MVA
MESSAGE
W1 POWER FACTOR:
0.00
The 745 calculates and displays real, reactive, and apparent power as well as the power
factor for all of the available windings providing that the voltage sensing is enabled. Power
flowing into the power transformer is designated as source power and power flowing out
of the transformer is designated as load power.
6.3.11 Energy
6.3.11.1 Main Menu
PATH: ACTUAL VALUES ZV A2 METERING ZV ENERGY
„ ENERGY
„ ENERGY DATA
[Z]
[Z]
CLEAR
MESSAGE
MESSAGE
MESSAGE
„ W1 ENERGY
[ Z]
„ W2 ENERGY
[ Z]
„ W3 ENERGY
[ Z]
See page 6–16
See page 6–16
See page 6–16
See page 6–16
The 745 calculates and displays watthours and varhours for source and load currents for
all available windings, providing that the voltage sensing is enabled.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
6–15
ACTUAL VALUESCHAPTER 6: ACTUAL VALUES
6.3.11.2 Energy Data Clear
PATH: ACTUAL VALUES ZV A2 METERING ZV ENERGY Z ENERGY DATA CLEAR
„ ENERGY DATA
CLEAR
[Z]
CLEAR ENERGY
DATA? No
MESSAGE
DATE OF LAST CLEAR:
Jan 01 1996
MESSAGE
TIME OF LAST CLEAR:
00:00:00
To clear all energy data, set CLEAR ENERGY DATA to “Yes”. The last date and time that the
energy data were cleared are also displayed. If the date has never been programmed, the
default values shown above appear.
6.3.11.3 Windings 1 to 3 Energy
PATH: ACTUAL VALUES ZV A2 metering ZV ENERGY ZV W1(3) ENERGY
„ W1 ENERGY
[ Z]
W1 SOURCE WATTHOURS:
0 MWh
MESSAGE
W1 LOAD WATTHOURS:
0 MWh
MESSAGE
W1 SOURCE VARHOURS:
0 Mvarh
MESSAGE
W1 LOAD VARHOURS:
0 Mvarh
The source and load watthours and varhours are displayed for winding 1. These messages
are repeated for windings 2 and 3.
6–16
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 6: ACTUAL VALUESACTUAL VALUES
6.4
A3 Event Recorder
6.4.1
Event Data Clear
PATH: ACTUAL VALUES ZV A3 EVENT RECORDER Z EVENT DATA CLEAR
„ EVENT DATA
CLEAR
[Z]
CLEAR EVENT DATA
RECORDER? No
MESSAGE
CLEAR EVENT RECORDER
SIGNAL: Disabled
MESSAGE
DATE OF LAST CLEAR:
Jan 01 1996
MESSAGE
TIME OF LAST CLEAR:
00:00:00.000
MESSAGE
NO. OF EVENTS SINCE
LAST CLEAR: 0
Enter “Yes” for the CLEAR EVENT DATA RECORDER to clear all event recorder data. The
CLEAR EVENT RECORDER SIGNAL actual value assigns a logic input to be used for remote
clearing of the event recorder. The last date and time the event data were cleared are also
displayed. If the date has never been programmed, the default values shown above
appear.
6.4.2
Event Records
PATH: ACTUAL VALUES ZV A3 EVENT RECORDER Z EVENT 001(256)
„ EVENT 001
[ Z]
EVENT DATE:
Jan 01 2001
MESSAGE
EVENT TIME:
00:00:00:000
MESSAGE
EVENT CAUSE: On
Control Power
MESSAGE
W1 PHASE A CURRENT
0 A at 0° Lag
MESSAGE
W1 PHASE B CURRENT
0 A at 0° Lag
MESSAGE
W1 PHASE C CURRENT
0 A at 0° Lag
MESSAGE
W1 GROUND CURRENT
0 A at 0° Lag
MESSAGE
W1 (% ƒo) H2a: 0.0
H2b: 0.0 H2c: 0.0
MESSAGE
W1 (% ƒo) H5a: 0.0
H5b: 0.0 H5c: 0.0
MESSAGE
W2 PHASE A CURRENT
0 A at 0° Lag
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
6–17
ACTUAL VALUESCHAPTER 6: ACTUAL VALUES
6–18
MESSAGE
W2 PHASE B CURRENT
0 A at 0° Lag
MESSAGE
W2 PHASE C CURRENT
0 A at 0° Lag
MESSAGE
W2 GROUND CURRENT
0 A at 0° Lag
MESSAGE
W2 (% ƒo) H2a: 0.0
H2b: 0.0 H2c: 0.0
MESSAGE
W2 (% ƒo) H5a: 0.0
H5b: 0.0 H5c: 0.0
MESSAGE
W3 PHASE A CURRENT
0 A at 0° Lag
MESSAGE
W3 PHASE B CURRENT
0 A at 0° Lag
MESSAGE
W3 PHASE C CURRENT
0 A at 0° Lag
MESSAGE
W3 GROUND CURRENT
0 A at 0° Lag
MESSAGE
W3 (% ƒo) H2a: 0.0
H2b: 0.0 H2c: 0.0
MESSAGE
W3 (% ƒo) H5a: 0.0
H5b: 0.0 H5c: 0.0
MESSAGE
PHASE A DIFFERENTIAL
CURRENT: 0.00 x CT
MESSAGE
PHASE B DIFFERENTIAL
CURRENT: 0.00 x CT
MESSAGE
PHASE C DIFFERENTIAL
CURRENT: 0.00 x CT
MESSAGE
PHASE A RESTRAINT
CURRENT: 0.00 x CT
MESSAGE
PHASE B RESTRAINT
CURRENT: 0.00 x CT
MESSAGE
PHASE C RESTRAINT
CURRENT: 0.00 x CT
MESSAGE
SYSTEM FREQUENCY:
0.00 Hz
MESSAGE
FREQUENCY DECAY
RATE: 0.00 Hz/s
MESSAGE
TAP CHANGER
POSITION: n/a
MESSAGE
VOLTS-PER-HERTZ:
0.00 V/Hz
MESSAGE
AMBIENT TEMPERATURE:
0°C
MESSAGE
ANALOG INPUT:
0 μA
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 6: ACTUAL VALUESACTUAL VALUES
The event record runs continuously, capturing and storing conditions present at the
moment of occurrence of the last 256 events, as well as the time and date of each event.
The header message for each event contains two pieces of information: the event number
(higher numbers denote more recent events) and the event date. If the event record is clear
or if the date has never been programmed, “Unavailable” is displayed instead of a date. No
more than 256 events are stored at the same time.
Pickup events are not recorded for elements that operate instantaneously (for example,
percent differential, instantaneous differential, etc.). Also, elements that have operate
times set to 0.00 seconds will not log pickup events. If the operate delay is set higher than
0.00, then the event recorder logs both the pickup and the operate events.
Table 6–1: Types and causes of events
PICKUP / OPERATE / DROPOUT Events
Percent Differential
Inst Differential
W1 Phase Time OC
W2 Phase Time OC
W3 Phase Time OC
W1 Phase Inst OC 1
W2 Phase Inst OC 1
W3 Phase Inst OC 1
W1 Phase Inst OC 2
W2 Phase Inst OC 2
W3 Phase Inst OC 2
W1 Neutral Time OC
W2 Neutral Time OC
W3 Neutral Time OC
W1 Neutral Inst OC 1
W2 Neutral Inst OC 1
W3 Neutral Inst OC 1
W1 Neutral Inst OC 2
W2 Neutral Inst OC 2
W3 Neutral Inst OC 2
W1 Ground Time OC
W2 Ground Time OC
W3 Ground Time OC
W1 Ground Inst OC 1
W2 Ground Inst OC 1
W3 Ground Inst OC 1
W1 Ground Inst OC 2
W2 Ground Inst OC 2
W3 Ground Inst OC 2
W1 Restd Gnd Fault
W2 Restd Gnd Fault
W3 Restd Gnd Fault
W1 Neg Seq Time OC
W2 Neg Seq Time OC
W3 Neg Seq Time OC
W1 Neg Seq Inst OC
W2 Neg Seq Inst OC
W3 Neg Seq Inst OC
Underfrequency 1
Underfrequency 2
Frequency Decay 1
Frequency Decay 2
Frequency Decay 3
Frequency Decay 4
Overfrequency
5th Harmonic Level
Volts-Per-Hertz 1
Volts-Per-Hertz 2
W1 THD Level
W2 THD Level
W3 THD Level
W1 Harmonic Derating
W2 Harmonic Derating
W3 Harmonic Derating
Analog Level 1
Analog Level 2
W1 Current Demand
W2 Current Demand
W3 Current Demand
Transformer Overload
Logic Input 1
Logic Input 2
Logic Input 3
Logic Input 4
Logic Input 5
Logic Input 6
Logic Input 7
Logic Input 8
Logic Input 9
Logic Input 10
Logic Input 11
Logic Input 12
Logic Input 13
Logic Input 14
Logic Input 15
Logic Input 16
Virtual Input 1
Virtual Input 2
Virtual Input 3
Virtual Input 4
Virtual Input 5
Virtual Input 6
Virtual Input 7
Virtual Input 8
Virtual Input 9
Virtual Input 10
Virtual Input 11
ON/OFF events
Virtual Input 12
Virtual Input 13
Virtual Input 14
Virtual Input 15
Virtual Input 16
Output Relay 1
Output Relay 2
Output Relay 3
Output Relay 4
Output Relay 5
Output Relay 6
Output Relay 7
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
6–19
ACTUAL VALUESCHAPTER 6: ACTUAL VALUES
Table 6–1: Types and causes of events (Continued)
Output Relay 8
Self-Test Relay
Virtual Output 1
Virtual Output 2
Virtual Output 3
Virtual Output 4
Virtual Output 5
Control Power
Test Mode
ERROR! events
Logic Input Power
Analog Output Power
Unit Not Calibrated
EEPROM Memory
Real-Time Clock
Emulation Software
Int. Temperature
FlexLogic Equation
DSP Processor
Bad Xfmr Settings
IRIG-B Signal
Setpt Access Denied
Ambnt temperature
The following events are always logged. That is, they are logged regardless of any event
recorder settings (they cannot be disabled).
Table 6–2: Continually logged events
Setpoint Group 1
Setpoint Group 2
Setpoint Group 3
Setpoint Group 4
Simulation Disabled
Simulation Prefault
Simulation Fault
Simulation Playback
Logic Input Reset
Front Panel Reset
Comm Port Reset
Manual Trace Trigger
Auto Trace Trigger
Aging Factor Limit
Ambient Temperature
Tap Changer Failure
Note
Note
6–20
The recorded event displayed for logic inputs, virtual inputs, and relay outputs will show
the programmed name of the input/output.
If Power to the SR745 is switched off before the relay is completely booted up and in
service, a false event could be recorded in the event recorder.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 6: ACTUAL VALUESACTUAL VALUES
6.5
A4 Product Information
6.5.1
Technical Support
PATH: ACTUAL VALUES ZV A4 PRODUCT INFO Z TECHNICAL SUPPORT
[ Z]
„ TECHNICAL
SUPPORT
GE Multilin
215 Anderson Avenue
MESSAGE
Markham, Ontario,
Canada, L6E 1B3
MESSAGE
Tel: (905) 294-6222
Fax: (905) 201-2098
MESSAGE
Internet Address:
GEindustrial.com/pm
The manufacturer’s contact information for technical support is shown here.
6.5.2
Revision Codes
PATH: ACTUAL VALUES ZV A4 PRODUCT INFO ZV REVISION CODES
„ REVISION
CODES
„„ 745 Transformer
„„ Management Relay
[Z]
MESSAGE
HARDWARE REVISION:
H
MESSAGE
FIRMWARE REVISION:
500
MESSAGE
BOOTWARE REVISION:
300
MESSAGE
VERSION NUMBER:
000
MESSAGE
INSTALLED OPTIONS:
W3-P1-G1-LO-ALR
MESSAGE
SERIAL NUMBER:
D33xxxxx
MESSAGE
MANUFACTURE DATE:
Jan 01 2006
Hardware and firmware revision codes are shown here.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
6–21
ACTUAL VALUESCHAPTER 6: ACTUAL VALUES
6.5.3
Calibration
PATH: ACTUAL VALUES ZV A4 PRODUCT INFO ZV CALIBRATION
„ CALIBRATION
[Z]
ORIGINAL CALBIRATION
DATE: Jan 01 2001
MESSAGE
LAST CALIBRATION
DATE: Jan 01 2001
The initial and most recent calibration dates are shown here.
6–22
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 6: ACTUAL VALUESACTUAL VALUES
6.6
Target and Flash Messages
6.6.1
Target Messages
Target messages are displayed when any protection, monitoring or self-test target is
activated. The messages contain information about the type of the active target(s), and are
displayed in a queue that is independent of both the setpoint and actual value message
structures.
When any target is active, the Message LED will turn on, and the first message in the queue
is displayed automatically. The target message queue may be scrolled through by pressing
the MESSAGE DOWN and UP keys.
As long as there is at least one message in the queue, the Message LED will remain lit.
Pressing any key other than MESSAGE DOWN or UP will return the display to the setpoint or
actual value message that was previously displayed. The MESSAGE DOWN and UP keys
may be pressed any time the Message LED is lit to re-display the target message queue.
If the MESSAGE RIGHT key is pressed when no target messages are in the queue, the
following flash message will appear:
NO ACTIVE TARGETS
A typical active target message looks like this,
„ LATCHED: a
„ Percent Differentl
and consists of three components which are arranged as follows:
„ <STATUS>: <PHASE>
„ <CAUSE>
The <STATUS> part of the above message will be one of PICKUP, OPERATE or LATCHED:
•
PICKUP: Indicates that the fault condition that is required to activate the protection
element has been detected by the 745 but has not persisted for a sufficiently long
time to cause the relay to activate its protection function.
•
OPERATE: Indicates that the protection element has been activated.
•
LATCHED: Indicates that the protection element is (or was) activated. This display will
remain even if the conditions that caused the element to activate are removed.
The <PHASE> part of the message represents the phase(s) that are associated with the
element (where applicable).
Messages for LATCHED targets remain in the queue until the relay is reset. Messages for
PICKUP and OPERATE targets remain in the queue as long as the condition causing the
target to be active is present. In addition, messages for LATCHED targets will automatically
be deleted if an entire week passes without any changes to the state of the target
messages but the conditions that caused the LATCHED messages to be displayed originally
are no longer present.
The bottom line of the display (i.e., <CAUSE>) will be the name of the element that has been
activated. These are as follows:
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
6–23
ACTUAL VALUESCHAPTER 6: ACTUAL VALUES
Table 6–3: Target message causes
Percent Differentl
Inst Differential
W1 Phase Time OC
W2 Phase Time OC
W3 Phase Time OC
W1 Phase Inst OC 1
W2 Phase Inst OC 1
W3 Phase Inst OC 1
W1 Phase Inst OC 2
W2 Phase Inst OC 2
W3 Phase Inst OC 2
W1 Ntrl Time OC
W2 Ntrl Time OC
W3 Ntrl Time OC
W1 Ntrl Inst OC 1
W2 Ntrl Inst OC 1
W3 Ntrl Inst OC 1
W1 Ntrl Inst OC 2
W2 Ntrl Inst OC 2
W3 Ntrl Inst OC 2
W1 Gnd Time OC
W2 Gnd Time OC
W3 Gnd Time OC
W1 Gnd Inst OC 1
W2 Gnd Inst OC 1
W3 Gnd Inst OC 1
W1 Gnd Inst OC 2
W2 Gnd Inst OC 2
W3 Gnd Inst OC 2
W1 Rest Gnd Fault
W2 Rest Gnd Fault
W3 Rest Gnd Fault
W1 Neg Seq Time OC
W2 Neg Seq Time OC
W3 Neg Seq Time OC
W1 Neg Seq Inst OC
W2 Neg Seq Inst OC
W3 Neg Seq Inst OC
Underfrequency 1
Underfrequency 2
Freq Decay Rate 1
Freq Decay Rate 2
Freq Decay Rate 3
Freq Decay Rate 4
Overfrequency
5th Harmonic Level
Volts-per-hertz 1
Volts-per-hertz 2
W1 THD Level
W2 THD Level
W3 THD Level
W1 Harmonic Derating
W2 Harmonic Derating
W3 Harmonic Derating
Analog Level 1
Analog Level 2
W1 Current Demand
W2 Current Demand
W3 Current Demand
Xformer Overload
Logic Input 1 (to 16)
Virtual Input 1 (to 16)
The recorded event displayed for logic inputs and virtual inputs will show the programmed
name of the input/output. An active target display may also be generated as a result of a
self-test error. When this occurs, the self-test error target message will be displayed Refer
to Self-test Errors on page 6–25 for a list of self-test error messages.
As well, there is an additional message that may appear as a target message. It looks like
this:
SETPOINTS HAVE NOT
BEEN PROGRAMMED!
This message will be placed in the target message queue whenever S1 745 SETUP ZV
INSTALLATION Z 745 SETPOINTS is set to “Not Programmed”. This serves as a warning that
the relay has not been programmed for the installation and is therefore not in the inservice state.
6–24
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 6: ACTUAL VALUESACTUAL VALUES
6.6.2
Self-test Errors
The 745 performs self-diagnostics at initialization (after power-up), and continuously
thereafter (in a background task). The tests ensure that every testable unit of the hardware
is functioning correctly.
Any self-test error indicates a serious problem requiring service.
Major self-test errors:
Upon detection of a major self-test error, the 745:
• disables all protection functionality
• turns on the front panel Self-Test Error LED
• turns off the front panel In Service LED
• de-energizes all output relays, including the self-test relay
• indicates the failure by inserting an appropriate message in the target message
queue
• records the failure in the event recorder
Minor self-test errors:
Upon detection of a minor self-test error, the 745:
• turns on the front panel Self-Test Error LED
• de-energizes the Self-Test Relay
• indicates the failure by inserting an appropriate message in the target message
queue
• records the failure in the event recorder
All conditions listed in the following table cause a target message to be generated.
Table 6–4: Self-test error interpretation
Event message
Target message
Severity
Cause
Logic Input Power
Self-Test Warning 0
Replace Immediately
Minor
This error is caused by failure of the
+32 V DC power supply used to
power dry contacts of logic inputs.
Logic inputs using internal power are
affected by this failure. This may be
caused by an external connection
which shorts this power supply to
ground.
Analog Output Power
Self-Test Warning 1
Replace Immediately
Minor
This error is caused by failure of the
+32 V DC power supply used to
power analog outputs. Analog
output currents are affected by this
failure.
Unit Not Calibrated
Unit Not Calibrated
Replace Immediately
Minor
This error message appears when
the 745 determines that it has not
been calibrated. Although the relay
is fully functional, the accuracy of
measured input values (e.g. currents
and line voltage) as well as
generated outputs (e.g. analog
outputs) is not likely to be within
those specified for the relay.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
6–25
ACTUAL VALUESCHAPTER 6: ACTUAL VALUES
Table 6–4: Self-test error interpretation (Continued)
Event message
6–26
Target message
Severity
Cause
EEPROM Memory
Self-Test Warning 2
Replace Immediately
Major
This error is caused by detection of
corrupted location in the 745 data
memory which cannot be selfcorrected. Errors that can be
automatically corrected are not
indicated. Any function of the 745 is
susceptible to maloperate from this
failure.
Clock Not Set
Clock Not Set
Program Date/Time
Minor
This error is caused when the 745
detects that the real-time clock is
not running. Under this condition,
the 745 will not be able to maintain
the current time and date. This
would normally occur if backup
power for the clock is lost and
control power is removed from the
745. Even if control power is
restored, the clock will not operate
until the time and/or date are
programmed via the S1 745 SETUP
ZV CLOCK menu.
Emulation Software
Self-Test Warning 4
Replace Immediately
Minor
This error is caused by development
software being loaded in the relay.
Int Temperature
Unit Temp. Exceeded
ServiceCheckAmbient
Minor
The relay has detected an
unacceptably low
(< –40ªC) or high (> 85°C)
temperature inside the unit.
Flexlogic Equation
Flexlogic Eqn Error
Consult User Manual
Major
This error is caused by the detection
of unacceptably low (less than –
40°C) or high (greater than +85°C)
temperatures detected inside the
unit
DSP Processor
Self-Test Warning 6
Replace Immediately
Major
This error is caused when
communications with the internal
digital signal processor is lost. Most
of the monitoring capability of the
745 (including all measurement of
current) will be lost when this failure
occurs.
Bad Xfmr Settings
Bad Xfmr Settings
Consult User Manual
Major
This error is caused when the 745
determines that the transformer
configuration programmed via
setpoints does not correspond to a
realistic physical system.
IRIG-B Signal
IRIG-B Error
Consult User Manual
Minor
This error is caused when the IRIG-B
signal type selected does not match
the format code being injected into
the IRIG-B terminals.
Setpt Access Denied
Setpoint Access Denied
Consult User Manual
Minor
This error is caused when the
passcode is entered incorrectly three
times in a row from either the front
panel or any of the communication
ports. This error may be removed by
entering the correct passcode.
Ambient Temperature
Amb. Temp. Exceeded
Check Ambient
Minor
This error is caused when ambient
temperature is out of range.(–50 to
250°C inclusive).
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 6: ACTUAL VALUESACTUAL VALUES
6.6.3
Flash Messages
Flash messages are warning, error, or general information messages displayed in response
to certain key presses. The length of time these messages remain displayed can be
programmed in S1 745 SETUP ZV PREFERENCES ZV FLASH MESSAGE TIME. The factory
default flash message time is 4 seconds.
ADJUSTED VALUE
HAS BEEN STORED
This flash message is displayed in response to pressing
ENTER while on a setpoint message with a numerical
value. The edited value had to be adjusted to the
nearest multiple of the step value before it was stored.
COMMAND IS BEING
EXECUTED
This flash message is displayed in response to
executing a command at a command message.
Entering “Yes” at a command message will display the
message ARE YOU SURE?. Entering “Yes” again will
perform the requested command, and display this
flash message.
DEFAULT MESSAGE
HAS BEEN ADDED
This flash message is displayed in response to pressing
the decimal key, followed by ENTER twice, on any
setpoint or actual value message except those in the
default messages subgroup.
DEFAULT MESSAGE
HAS BEEN REMOVED
This flash message is displayed in response to pressing
the decimal key, followed by ENTER twice, on one of
the selected default messages in the default messages
subgroup.
ENTERED PASSCODE
IS INVALID
This flash message is displayed in response to an
incorrectly entered passcode when attempting to
enable or disable setpoint access. It is also displayed
when an attempt has been made to upgrade to an
option without the correct passcode.
ENTRY MISMATCH –
CODE NOT STORED
This flash message is displayed while changing the
programmed passcode from the change passcode
command. If the passcode entered at the prompt
PLEASE RE-ENTER NEW PASSCODE is different from the
one entered at the prompt PLEASE ENTER A NEW
PASSCODE, the 745 will not store the entered
passcode, and display this flash message.
INPUT FUNCTION IS
ALREADY ASSIGNED
(a) This flash message is displayed under certain
conditions when attempting to assign logic input
functions under S3 LOGIC INPUTS. Only the “Disabled”
and “To FlexLogic” functions can be assigned to more
than one logic input. If an attempt is made to assign
any another function to a logic input when it is already
assigned to another logic input, the assignment will
not be made and this message will be displayed,
(b) Ground Input Selection settings also use this flash
message.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
6–27
ACTUAL VALUESCHAPTER 6: ACTUAL VALUES
6–28
INVALID KEY: MUST
BE IN LOCAL MODE
This flash message is displayed in response to pressing
RESET while the 745 is in remote mode. The 745 must
be put into local mode in order for this key to be
operational.
INVALID SERIAL
NUMBER
This flash message is displayed when an attempt is
made to upgrade installed options and the 745 detects
an invalid serial number.
NEW PASSCODE HAS
BEEN STORED
This flash message is displayed in response to
changing the programmed passcode from the
setpoint S1 745 SETUP Z PASSCODE ZV CHANGE
PASSCODE. The directions to change the passcode
were followed correctly, and the new passcode was
stored as entered.
NEW SETPOINT HAS
BEEN STORED
This flash message is displayed in response to pressing
ENTER while editing on any setpoint message. The
edited value was stored as entered.
NO ACTIVE TARGETS
(TESTING LEDS)
This flash message is displayed in response to the
MESSAGE UP or DOWN key while the Message LED is
off. There are no active conditions to display in the
target message queue.
OUT OF RANGE –
VALUE NOT STORED
This flash message is displayed in response to pressing
ENTER while on a setpoint message with a numerical
value. The edited value was either less than the
minimum or greater than the maximum acceptable
value for this setpoint and, as a result, was not stored.
PASSCODE VALID OPTIONS ADJUSTED
This flash message is displayed when an attempt to
upgrade an option was successful.
PLEASE ENTER A
NON-ZERO PASSCODE
This flash message is displayed while changing the
passcode from the S1 745 SETUP Z PASSCODE ZV
CHANGE PASSCODE setpoint. An attempt was made to
change the passcode to “0” when it was already 0.
PRESS [ENTER] TO
ADD AS DEFAULT
This flash message is displayed for 5 seconds in
response to pressing the decimal key followed by
ENTER while displaying any setpoint or actual value
message except the S1 745 SETUP ZV DEFAULT
MESSAGES ZV SELECTED DEFAULTS setpoint. Pressing
ENTER again while this message is displayed adds the
setpoint or actual value message to the default list.
PRESS [ENTER] TO
BEGIN TEXT EDIT
This flash message is displayed in response to pressing
the VALUE keys while on a setpoint message with a
text entry value. The ENTER key must first be pressed
to begin editing.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 6: ACTUAL VALUESACTUAL VALUES
PRESS [ENTER] TO
REMOVE MESSAGE
This flash message is displayed for 5 seconds in
response to pressing the decimal key followed by
ENTER while displaying one of the selected default
messages in the S1 745 SETUP ZV DEFAULT MESSAGES
ZV SELECTED DEFAULTS menu. Pressing ENTER again
while this message is displayed removes the default
message.
PRESSED KEY
IS INVALID HERE
This flash message is displayed in response to any
pressed key that has no meaning in the current
context.
RESETTING LATCHED
CONDITIONS
This flash message is displayed in response to pressing
RESET when the relay is in local mode. All active
targets for which the activating condition is no longer
present will be cleared.
SETPOINT ACCESS
DENIED (PASSCODE)
This flash message is displayed in response to pressing
ENTER while on any setpoint message. Setpoint access
is restricted because the programmed passcode has
not been entered to allow access.
SETPOINT ACCESS
DENIED (SWITCH)
This flash message is displayed in response to pressing
ENTER while on any setpoint message. Setpoint access
is restricted because the setpoint access terminals
have not been connected.
SETPOINT ACCESS
IS NOW ALLOWED
This flash message is displayed in response to entering
the programmed passcode at the S1 745 SETUP ZV
PASSCODE ZV ALLOW SETPOINT WRITE ACCESS
setpoint. The command to allow write access to
setpoints has been successfully executed and
setpoints can be changed and entered.
SETPOINT ACCESS
IS NOW RESTRICTED
This flash message is displayed in response to
correctly entering the programmed passcode at S1
745 SETUP ZV PASSCODE ZV ALLOW SETPOINT WRITE
ACCESS. The command to restrict access to setpoints
has been successfully executed and setpoints cannot
be changed.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
6–29
ACTUAL VALUESCHAPTER 6: ACTUAL VALUES
6–30
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
GE Consumer & Industrial
Multilin
745 Transformer Protection
System
Chapter 7: Commissioning
Commissioning
7.1
General
7.1.1
Introduction
The procedures contained in this section can be used to verify the correct operation of the
745 Transformer Protection System prior to placing it into service for the first time. These
procedures may also be used to verify the relay on a periodic basis. Although not a total
functional verification, the tests in this chapter verify the major operating points of all
features of the relays. Before commissioning the relay, users should read the installation
chapter, which provides important information about wiring, mounting, and safety
concerns. The user should also become familiar with the relay as described in the setpoints
and actual values chapters.
Test personnel must be familiar with general relay testing practices and safety precautions
to avoid personal injuries or equipment damage.
This chapter is divided into several sections, as follows:
• GENERAL: outlines safety precautions, conventions used in the test procedures.
• TEST EQUIPMENT: the test equipment required.
• GENERAL PRELIMINARY WORK
• LOGIC INPUTS AND OUTPUT RELAYS: tests all digital and analog inputs, the
analog-to-digital data acquisition system, and relay and transistor outputs.
• DISPLAY, METERING, COMMUNICATIONS, ANALOG OUTPUTS: tests all values
derived from the AC current and voltage inputs.
• PROTECTION SCHEMES: tests all features that can cause a trip, including
differential, overcurrent, over and underfrequency elements.
• AUXILIARY PROTECTION/MONITORING FUNCTIONS
• PLACING RELAY INTO SERVICE
• SETPOINT TABLES
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–1
COMMISSIONINGCHAPTER 7: COMMISSIONING
7.1.2
Testing Philosophy
The 745 is realized with digital hardware and software algorithms, using extensive internal
monitoring. Consequently, it is expected that, if the input circuits, CTs, VTs, power supply,
auxiliary signals, etc., are functioning correctly, all the protection and monitoring features
inside the relay will also perform correctly, as per applied settings. It is therefore only
necessary to perform a calibration of the input circuits and cursory verification of the
protection and monitoring features to ensure that a fully-functional relay is placed into
service.
Though tests are presented in this section to verify the correct operation of all features
contained in the 745, only those features which are placed into service need be tested.
Skip all sections which cover features not included or not enabled when the relay is in
service, except for the provision of the next paragraph.
Some features such as the Local/Remote Reset of targets, display messages and
indications are common to all the protection features and hence are tested only once.
Testing of these features has been included with the Harmonic Restraint Percent
Differential, which will almost always be enabled. If, for some reasons, this element is not
enabled when the relay is in service, you will need to test the Local/Remote Reset when
testing another protection element.
7.1.3
Safety Precautions
Ensure the following precautions are observed before testing the relay.
HIGH VOLTAGES ARE PRESENT ON THE REAR TERMINALS OF THE RELAY, CAPABLE OF
CAUSING DEATH OR SERIOUS INJURY. USE CAUTION AND FOLLOW ALL SAFETY RULES
WHEN HANDLING, TESTING, OR ADJUSTING THE EQUIPMENT.
DO NOT OPEN THE SECONDARY CIRCUIT OF A LIVE CT, SINCE THE HIGH VOLTAGE
PRODUCED IS CAPABLE OF CAUSING DEATH OR SERIOUS INJURY, OR DAMAGE TO THE
CT INSULATION.
THE RELAY USES COMPONENTS WHICH ARE SENSITIVE TO ELECTROSTATIC DISCHARGES.
WHEN HANDLING THE UNIT, CARE SHOULD BE TAKEN TO AVOID ELECTRICAL
DISCHARGES TO THE TERMINALS AT THE REAR OF THE RELAY.
ENSURE THAT THE CONTROL POWER APPLIED TO THE RELAY, AND THE AC CURRENT
AND VOLTAGE INPUTS, MATCH THE RATINGS SPECIFIED ON THE RELAY NAMEPLATE. DO
NOT APPLY CURRENT TO THE CT INPUTS IN EXCESS OF THE SPECIFIED RATINGS.
ENSURE THAT THE LOGIC INPUT WET CONTACTS ARE CONNECTED TO VOLTAGES BELOW
THE MAXIMUM VOLTAGE SPECIFICATION OF 300 V DC.
7.1.4
Conventions
The following conventions are used for the remainder of this chapter:
7–2
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
•
All setpoints and actual values are mentioned with their path as a means of specifying
where to find the particular message. For instance, the setpoint WINDING 1 PHASE CT
PRIMARY, which in the message structure is located under setpoints page S2, would be
written as:
S2 SYSTEM SETUP ZV WINDING 1 ZV WINDING 1 PHASE CT PRIMARY
7.1.5
•
Normal phase rotation of a three-phase power system is ABC.
•
The phase angle between a voltage signal and a current signal is positive when the
voltage leads the current.
•
Phase A to neutral voltage is indicated by Van (arrowhead on the “a”).
•
Phase A to B voltage is indicated by Vab (arrowhead on the “a”).
•
The neutral current signal is the 3Io signal derived from the three phase currents for
any given winding.
•
The ground current is the current signal measured by means of a CT in the power
transformer connection to ground.
Test Equipment
It is possible to completely verify the 745 relay operation using the built-in test and
simulation features described earlier in this manual. However, some customers prefer to
perform simple signal-injection tests to verify the basic operation of each element placed
into service. The procedures described in this chapter have been designed for this purpose.
To use the built-in facilities, refer to the appropriate sections in this manual.
The conventional, decades-old approach to testing relays utilized adjustable voltage and
current sources, variacs, phase shifters, multimeters, timing device, and the like. In the last
few years several instrumentation companies have offered sophisticated instrumentation
to test protective relays. Generally this equipment offers built-in sources of AC voltage and
current, DC voltage and current, timing circuit, variable frequency, phase shifting,
harmonic generation, and complex fault simulation. If using such a test set, refer to the
equipment manufacturer's instructions to generate the appropriate signals required by the
procedures in this section. If you do not have a sophisticated test set, then you will need
the following ‘conventional’ equipment:
• Variable current source able to supply up to 40 A (depends on relay settings)
• Variable power resistors to control current amplitude
• Ten-turn 2 kΩ low-power potentiometer
• Power rectifier to build a circuit to generate 2nd harmonics
• Accurate timing device
• Double-pole single-throw contactor suitable for at least 40 amperes AC.
• Combined fundamental and 5th-harmonic adjustable current supply for elements
involving the 5th harmonic.
• Variable-frequency source of current or voltage to test over/underfrequency and
frequency trend elements.
• Ammeters (RMS-responding), multimeters, voltmeters
• variable DC mA source
• variable DC mV source
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–3
COMMISSIONINGCHAPTER 7: COMMISSIONING
• single-pole single-throw contactor
The simple test setup shown below can be used for the majority of tests. When the diode is
not shorted and the two currents are summed together prior to the switch, the composite
current contains the 2nd harmonic necessary to verify the 2nd harmonic restraint of the
harmonic restraint percent differential elements. With the diode shorted and the two
currents fed to separate relay inputs, the slope of the differential elements can be
measured. With only I1 connected (with a return path) the pickup level of any element can
be measured.
FIGURE 7–1: Test setup
7–4
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
7.2
Preliminary Work
7.2.1
Description
Z Review appropriate sections of this manual to familiarize yourself with
the relay. Confidence in the commissioning process comes with
knowledge of the relay features and methods of applying settings.
Z Verify the installation to ensure correct connections of all inputs and
outputs.
Z Review the relay settings and/or determine features and settings
required for your installation. In large utilities a central group is often
responsible for determining which relay features will be enabled and
which settings are appropriate. In a small utility or industrial user, the
on-site technical person is responsible both for the settings and also for
the complete testing of the relay.
Z Set the relay according to requirements.
Ensure that the correct relay model has been installed. A summary table
is available in this manual for users to record all the relay settings.
Z When the testing is completed, verify the applied relay settings, and
verify that all desired elements have been enabled, using the EnerVista
745 Setup software or the relay front panel.
Z Verify that the relay rated AC current matches the CT secondary value.
Z Verify that the relay rated AC voltage matches the VT secondary value.
Z Verify that the relay rated frequency setting matches the power system
frequency.
Z Open all blocking switches so as not to issue an inadvertent trip signal to
line breakers.
Z Verify that the auxiliary supply matches relay nameplate. Turn the
auxiliary supply on.
Z Verify that all grounding connections are correctly made.
To facilitate testing it is recommended that all functions be initially set to Disabled. Every
feature which will be used in the application should be set per desired settings, enabled for
the specific commissioning test for the feature, then returned to Disabled at completion of
its test. Each feature can then be tested without complications caused by operations of
other features. At the completion of all commissioning tests all required features are then
Enabled.
It is necessary to keep track of modifications/changes made to settings during the
course of these commissioning steps and ensure that all settings are returned to the
‘in-service’ values at the end of the tests, prior to placing the relay into service.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–5
COMMISSIONINGCHAPTER 7: COMMISSIONING
7.2.2
Dielectric Strength Testing
The 745 is rated for 1.9 kV AC for 1 second or 1.6 kV for 1 minute (as per UL 508) isolation
between relay contacts, CT inputs, VT inputs and the safety ground terminal G12. Some
precautions are required to prevent 745 damage during these tests.
Filter networks and transient protection clamps are used between control power and the
filter ground terminal G11. This filtering is intended to filter out high voltage transients,
radio frequency interference (RFI), and electromagnetic interference (EMI). The filter
capacitors and transient suppressors could be damaged by application continuous high
voltage. Disconnect filter ground terminal G11 during testing of control power and trip coil
supervision. CT inputs, VT inputs, and output relays do not require any special precautions.
Low voltage inputs (< 30 V) such as RTDs, analog inputs, analog outputs, digital inputs, and
RS485 communication ports are not to be tested for dielectric strength under any
circumstance.
GE Multilin
FIGURE 7–2: Testing for dielectric strength
7–6
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
7.3
Logic Inputs and Output Relays
7.3.1
Logic Inputs
The dry and wet contact connections are shown below:
FIGURE 7–3: Logic inputs
Z Prior to energizing any of the Logic Inputs, ensure that doing so will not
cause a relay trip signal to be issued beyond the blocking switches.
These should have been opened prior to starting on these tests. If you
wish, you can disable the Logic Input functions by setting:
• S3 LOGIC INPUTS ZV LOGIC INPUT 1 (16) ZV LOGIC INPUT 1(16)
FUNCTION: “Disabled”
Z Connect a switch between Logic Input 1 (Terminal D1) and +32 V DC
(Terminal D12), as shown above (alternatively, use the wet contact
approach shown in the same figure).
Logic Inputs can be asserted with either an opened or closed contact, per
the user choice. Verify/set the type of Logic Input to be used with the
following setpoint:
• S3 LOGIC INPUTS ZV LOGIC INPUTS ZV LOGIC INPUT 1 (16) ZV
INPUT 1(16) ASSERTED STATE
Z Display the status of the Logic Input using the A1 STATUS ZV LOGIC
INPUTS ZV LOGIC INPUT 1(16) STATE actual value.
Z With the switch contact open (or closed), check that the input state is
detected and displayed as Not Asserted.
Z Close (open) the switch contacts. Check that the input state is detected
and displayed as Asserted.
Z Repeat for all the relay logic inputs which are used in your application.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–7
COMMISSIONINGCHAPTER 7: COMMISSIONING
7.3.2
Output Relays
Z To verify the proper functioning of the output relays, enable the Force
Output Relays function by setting:
• S6 TESTING Z OUTPUT RELAYS Z FORCE OUTPUT RELAYS
FUNCTION: Enabled
The Test Mode LED on the front of the relay will come ON,
indicating that the relay is in test mode and no longer in service.
In test mode all output relays can be controlled manually.
Z Under S6 TESTING ZV OUTPUT RELAYS set the FORCE OUTPUT 1 to
FORCE OUTPUT 8 setpoints to De-energized.
Z Using a multimeter, check that all outputs are de-energized.
For outputs 2 to 5, the outputs are dry N.O. contacts and for outputs 6 to
8, the outputs are throw-over contacts (form-C). Output 1 is a solid state
output. When de-energized, the resistance across E1 and F1 will be
greater than 2 MΩ; when energized, and with the multimeter positive
lead on E1, the resistance will be 20 to 30 kΩ.
Z Now change the FORCE OUTPUT 1 to FORCE OUTPUT 8 setpoints to
Energized.
Z Using a multimeter, check that all outputs are now energized.
Z Now return all output forcing to De-energized and disable the relay
forcing function by setting S6 TESTING Z OUTPUT RELAYS Z FORCE
OUTPUT RELAYS FUNCTION to Disabled.
All the output relays should reset.
7–8
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
7.4
Metering
7.4.1
Description
Accuracy of readings taken in this section should be compared with the specified
accuracies in Specifications on page 2–5. If the measurements obtained during this
commissioning procedure are ‘out-of-specification’ verify your instrumentation accuracy.
If the errors are truly in the relay, advise the company representative.
7.4.2
Current Inputs
The general approach used to verify the AC current inputs is to supply rated currents in all
the input CTs. Displayed readings will then confirm that the relay is correctly measuring all
the inputs and performing the correct calculations to derive sequence components,
loading values, etc. Since the displayed values are high-side values, you can use this test to
verify that the CT ratios have been correctly entered.
Z If you are using a single phase current supply, connect this current signal
to all the input CTs in series, winding 1, 2 and 3, if using a threewinding configuration, and the ground CT input(s). Adjust the current
level to 1 A for 1-amp-rated relays and to 5 A for 5-amp-rated relays.
Some elements may operate under these conditions unless all
elements have been disabled!
Z With the above current signals ON, read the actual values displayed
under A2 METERING Z CURRENT.
The actual values can be quickly read using the EnerVista 745 Setup
software.
Z Read the RMS magnitude and the phase of the current signal in each
phase of each winding.
Note that the Winding 1 Phase A current is used as the reference for
all angle measurements.
Iphase rms displayed = Iphase input x CT ratio for that winding
The phase angle will be 0° for all phase currents if the same current is injected in all phase
input CTs. Sequence components will be:
2
I a + aI b + a I c
I 1 = CT Ratio × ---------------------------------- = 0, all 3 currents in phase, and a = ∠120°
3
2
I a + a I b + aI c
I 2 = CT Ratio × ---------------------------------- = 0, the 3 currents are in phase
3
I zero-sequence = CT Ratio × input current
(EQ 7.1)
I neutral = 3 × CT Ratio × input current
I ground = Ground CT Ratio × input current into Ground CT
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–9
COMMISSIONINGCHAPTER 7: COMMISSIONING
Since the transformer load is calculated using the maximum current from phases A, B, or C,
the displayed load should be:
Actual Current
% Loading = ------------------------------------------------ × 100%
Rated MVA Current
MVA where Rated MVA Current = ---------------------3kV L – L
(EQ 7.2)
Z Verify the harmonic content display in A2 METERING ZV HARMONIC
CONTENT ZV THD ZV W1...W2...W3.
It should be zero or equal to distortion of input current.
Z Verify frequency shown in A2 METERING ZV FREQUENCY ZV
SYSTEM FREQUENCY.
It should be 60 or 50 Hz, as per frequency of input current on Phase A.
Z To verify the positive and negative sequence component values, apply
the current signal to Phase A of each winding in series.
Read the values of positive and negative sequence current displayed by
the relay.
1
1
2
I 1 = --- × CT Ratio × ( I a + aI b + a I c ) = --- × CT Ratio × I a
3
3
since I b = I c = 0
(EQ 7.3)
where a = 1∠120°
1
1
2
I 2 = --- × CT Ratio × ( I a + a I b + aI c ) = --- × CT Ratio × I a
3
3
since I b = I c = 0
(EQ 7.4)
All angles will be 0°. These values are displayed in the A2 METERING Z CURRENT ZV
POSITIVE SEQUENCE ZV W1...W2...W3 and A2 METERING Z CURRENT ZV NEGATIVE
SEQUENCE ZV W1...W2...W3 actual values menus.
Z Lower the current amplitude while displaying the system frequency.
Z Verify that the frequency is displayed correctly with current levels down
to approximately 50 mA RMS input.
Z Decrease current to 0 A.
7.4.3
Voltage Input
Z Connect an AC voltage to the voltage input (if the input voltage feature
is enabled) to terminals C11 and C12.
Z Set the level at the expected VT secondary voltage on the VT for your
installation.
Z Remove all current signals from the relay.
Z Verify the voltage reading in A2 METERING ZV VOLTAGE ZV SYSTEM
LINE-TO-LINE VOLTAGE.
The reading should be equal to the input voltage × VT ratio.
Note
7–10
The displayed system voltage is always the line-to-line voltage regardless of the input
VT signal. Earlier versions of the 745 may display the same voltage as the selected
input, i.e. phase-to-neutral if the input is a phase-to-neutral signal and phase-tophase if the input is phase-to-phase.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
Z With the voltage signal still ON, read the displayed system frequency
under A2 METERING ZV FREQUENCY Z SYSTEM FREQUENCY.
Z Lower the voltage amplitude while displaying the system frequency.
Z Verify that the frequency is displayed correctly with voltage levels down
to less than 3 V RMS input (when the lower limit is reached, the system
frequency will be displayed as 0.00 Hz).
Z Verify that at less than 1.0 V, frequency is displayed as 0.00 Hz.
7.4.4
Transformer Type Selection
7.4.4.1 Description
The 745 automatically configures itself to correct for CT ratio mismatch, phase shift, etc.,
provided that the input CTs are all connected in wye. The following example illustrates the
automatic setting feature of the 745.
7.4.4.2 Automatic Transformation
The automatic configuration routines examine the CT ratios, the transformer voltage
ratios, the transformer phase shift, etc., and apply correction factors to match the current
signals under steady state conditions.
Consider the case of a Y:D30° power transformer with the following data (using a 1 A CT
secondary rating for the relay):
• Winding 1: 100 MVA, 220 kV, 250/1 CT ratio (rated current is 262.4 A, hence CT ratio
of 250/1)
• Winding 2: 100 MVA, 69 kV, 1000/1 CT ratio (rated current is 836.8 A, hence CT ratio
of 1000/1)
The 1000/1 CT ratio is not a perfect match for the 250/1 ratio. The high-side CT produces a
secondary current of 262.5/250 = 1.05 A whereas the low-side CT produces a current of
0.837 A. The 745 automatically applies an amplitude correction factor to the Winding 2
currents to match them to the Winding 1 currents. The following illustrates how the
correction factor is computed:
V1
250 220 V
CT 2 ( ideal ) = CT 1 × ----- = --------- × -------------- = 797.1
V2
1
69 V
(EQ 7.5)
The mismatch factor is therefore:
Ideal CT Ratio- = 797.1
------------------------------------------------- = 0.7971
Actual CT Ratio
1000
(EQ 7.6)
Winding 2 currents are divided by this factor to obtain balanced conditions for the
differential elements.
If this transformer were on line, fully loaded, and protected by a properly set 745 relay, the
actual current values read by the relay would be:
• Winding 1: 262.5 A ∠0° (this is the reference winding)
• Winding 2: 836.8 A ∠210° (30° lag due to transformer and 180° lag due to CT
connections)
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–11
COMMISSIONINGCHAPTER 7: COMMISSIONING
• Differential current: < 0.03 × CT as the two winding currents are equal once
correctly transformed inside the relay.
• The loading of each winding would be 100% of rated.
The above results can be verified with two adjustable sources of three-phase current. With
a single current source, how the relay performs the necessary phase angle corrections
must be taken into account. Table 5–1: Transformer types on page 5–13 shows that the Yside currents are shifted by 30° to match the Delta secondary side. The 30° phase shift is
obtained from the equations below:
I W1a – I W1c
I W1b – I W1a
I W1c – I W1b
I W1a′ = --------------------------- , I W1b′ = ---------------------------- , I W1c′ = --------------------------3
3
3
(EQ 7.7)
By injecting a current into Phase A of Winding 1 and Phase A of Winding 2 only, IW1b = IW1c
= 0 A. Therefore, if we assume an injected current of 1 × CT, the transformed Y-side currents
will be:
1 × CT
– 1 × CT
× CT
I W1a′ = --------------- , I W1b′ = ------------------- , I W1c′ = 0
--------------3
3
3
(EQ 7.8)
For the purposes of the differential elements only, the transformation has reduced the
current to 0.57 times its original value into Phase A, and created an apparent current into
Phase B, for the described injection condition. If a 1 × CT is now injected into Winding 1
Phase A, the following values for the differential currents for all three phases should be
obtained:
Phase A differential: 0.57 × CT ∠0° Lag
Phase B differential: 0.57 × CT ∠180° Lag
Phase C: 0 × CT.
7.4.4.3 Effects of Zero-sequence Compensation Removal
Note
The transformation used to obtain the 30° phase shift on the Y-side automatically
removes the zero-sequence current from those signals. The 745 always removes the
zero-sequence current from the delta winding currents.
If the zero-sequence component is removed from the Delta-side winding currents, the
Winding 2 current values will change under unbalanced conditions. Consider the case
described above, with the 1 × CT injected into Phase A of Winding 2.
For the 1 × CT current, the zero-sequence value is 1/3 of 1.0 × CT or 0.333 × CT A. The value
for IW2a' is therefore (1.0 – 0.333) × CT = 0.6667 × CT A. This value must be divided by the CT
error correction factor of 0.797 as described above.
Therefore, the value of differential current for Phase A, when injecting 1 × CT in Winding 2
only, is:
× CT A- = 0.84 × CT A
I A ( differential ) = 0.667
-----------------------------0.797
(EQ 7.9)
The action of removing the zero-sequence current results in a current equal to the zerosequence value introduced into phases B and C. Hence, the differential current for these
two elements is:
× CT A- = 0.42 × CT A
I B ( differential ) = I C ( differential ) = 0.333
-----------------------------0.797
7–12
(EQ 7.10)
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
Now, applying 1 × CT into Winding 1 Phase A and the same current into Phase A Winding 2,
but 180° out-of- phase to properly represent CT connections, the total differential current
in the Phase A element will be (0.57 – 0.84) × CT = –0.26 × CT. The injection of currents into
Phase A of Windings 1 and 2 in this manner introduces a differential current of (–0.57 × CT
+ 0.42 × CT) = –0.15 × CT into Phase B and (0.0 × CT + 0.42 × CT) = 0.42 × CT into Phase C.
7.4.5
Ambient Temperature Input
7.4.5.1 Basic Calibration of RTD Input
Z Enable ambient temperature sensing with the S2 SYSTEM SETUP ZV
AMBIENT TEMP Z AMBIENT TEMPERATURE SENSING setpoint.
Z Connect a thermocouple to the relay terminals B10, B11, and B12 and
read through the A2 METERING ZV AMBIENT TEMP Z AMBIENT
TEMPERATURE actual value.
Z Compare the displayed value of temperature against known temperature
at the location of the sensor.
Use a thermometer or other means of obtaining actual temperature.
An alternative approach is to perform a more detailed calibration per the procedure
outlined below.
7.4.5.2 Detailed Calibration of RTD Input
1.
Alter the following setpoints. Set S2 SYSTEM SETUP ZV AMBIENT TEMP Z AMBIENT
TEMPERATURE SENSING to Enabled and set S2 SYSTEM SETUP ZV AMBIENT TEMP ZV
AMBIENT RTD TYPE to the desired type.
The measured values should be ±2°C or ±4°F.
2.
Alter the resistance applied to the RTD input (note the 3-input connection must be
used for the measurements to be valid) as per the typical table below to simulate RTDs
and verify accuracy of the measured values.
3.
View the measured values in A2 METERING ZV AMBIENT TEMP Z AMBIENT
TEMPERATURE.
Refer to RTD tables included in this manual for calibration of resistance versus
temperature.
Table 7–1: Measured RTD temperature
RTD type
100 Ω Platinum
resistance
Expected RTD reading
°C
°F
80.31
–50
–58
100.00
0
32
119.39
50
122
138.50
100
212
157.32
150
302
175.84
200
392
194.08
250
482
100 Ω Platinum
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
Measured RTD temperature
____°C ____°F (select one)
7–13
COMMISSIONINGCHAPTER 7: COMMISSIONING
Table 7–1: Measured RTD temperature
RTD type
120 Ω Nickel
100 Ω Nickel
100 Ω Platinum
resistance
Expected RTD reading
°C
°F
86.17
–50
–58
120.0
0
32
157.74
50
122
200.64
100
212
248.95
150
302
303.46
200
392
366.53
250
482
71.81
–50
–58
100.00
0
32
131.45
50
122
167.20
100
212
207.45
150
302
252.88
200
392
305.44
250
482
Measured RTD temperature
____°C ____°F (select one)
7.4.5.3 Ambient Temperature by Monthly Averages
Z If the ambient temperature is entered as 12 monthly averages, program
the value for the month during which the relay is being commissioned.
Z Examine the A2 METERING ZV AMBIENT TEMP Z AMBIENT
TEMPERATURE actual value to verify the programmed temperature.
Z Verify that values entered for other months do not affect the value for
the present month.
7.4.6
Analog outputs
The analog output settings are located in the S2 SYSTEM SETUP ZV ANALOG OUTPUTS
setpoints section.
Z Connect a milliammeter to the analog output contacts: COM on A5 and
analog output 1 on A6, analog output 2 on A7, analog output 3 on A8,
analog output 4 on A9, analog output 5 on A10, analog output 6 on A11,
or analog output 7 on A12.
Z From the settings used for the tested analog output, determine the mA
range for the output and the driving signal and its range for the full
range of output current.
Z Apply the input signal and vary its amplitude over the full range and
ensure the analog output current is the correct amplitude.
Z Record the results in the table below.
Z Duplicate as required for each analog output.
7–14
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
Table 7–2: Analog Output Calibration Results
Analog output number: __________ Analog output minimum: ______________
Analog output value: ___________
Analog output maximum: ___________
Analog output range: ____________
Input signal amplitude
(% of full range)
Expected mA output
Measured mA output
0
25
50
75
100
7.4.7
Tap Position
The analog input used to sense tap position is programmed with the S2 SYSTEM SETUP ZV
ONLOAD TAP CHANGER setpoints.
Z To verify the operation of this circuit, connect a variable resistor across
terminals A3 and A4.
The resistor range should cover the full range of resistance produced by
the tap changer mechanism. The tap position is displayed in A2
METERING ZV TAP CHANGER Z TAP CHANGER POSITION.
Z Adjust the resistance to simulate the minimum tap position and verify
that a “1” is displayed.
Z Gradually increase the resistance up to the value which represents the
maximum tap value, verifying that the tap position indicator tracks the
resistance.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–15
COMMISSIONINGCHAPTER 7: COMMISSIONING
7.5
Protection Schemes
7.5.1
Precaution
Keep track of modifications/changes made to settings during the course of these
commissioning steps and ensure that all settings are returned to the ‘in-service’ values
at the end of the tests.
7.5.2
Harmonic Restrained Percent Differential
7.5.2.1 Description
The harmonic restrained percent differential element setpoints are located in S4 ELEMENTS
ZV DIFFERENTIAL Z PERCENT DIFFERENTIAL . Disable all other protection elements to
ensure that trip relay(s) and auxiliary relays are operated by element under test only. With
a multimeter, monitor the appropriate output contact(s) per intended settings of the
FlexLogic™. Refer to the relay settings to find out which relay(s) should operate when a
given element operates.
7.5.2.2 Minimum Pickup
The minimum pickup of the phase A element is measured by applying a fundamental
frequency AC current to terminals H1 and G1, winding 1 phase A. Monitor the appropriate
trip and auxiliary contact(s) as the current is increased from 0 A. Compare the current value
at which operation is detected against the S4 ELEMENTS ZV DIFFERENTIAL Z PERCENT
DIFFERENTIAL ZV PERCENT DIFFERENTIAL PICKUP setpoint. Since the operating point is
normally set quite low, fine control of the current signal will be required to obtain accurate
results.
The currents in the winding may be phase shifted or may have the zero-sequence
component removed due to auto-configuration (see Auto-configuration on page 5–6). As
an alternate to calculating to relation of input current to differential current, the differential
current is displayed in A2 METERING Z CURRENT ZV DIFFERENTIAL. Ensure that the
displayed value is the same as the minimum pickup setting when the element operates.
Z Check that the Trip and Message LEDs are flashing and one of the
following trip messages is displayed:
LATCHED a: Percent Differential, or OPERATED a: Percent
Differential
Note
The above messages will indicate either OPERATED or LATCHED depending on the S4
ELEMENTS ZV DIFFERENTIAL Z PERCENT DIFFERENTIAL ZV PERCENT DIFFERENTIAL
TARGET setting.
To independently verify that auto-configuration causes the currents to be as measured,
follow the rules outlined in the steps below.
Z Look up transformer type in Table 5–1: Transformer types on page 5–
13.
7–16
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
Z For the phase shift for the particular set of vectors, determine the
processing applied to the current vectors for that winding from Table 5–
2: Phase shifts on page 5–24.
Z Calculate the “dashed” current values using the equations in Table 5–2:
Phase shifts on page 5–24.
If applicable, use the zero-sequence removal computation. This is
applicable for all Delta windings and for both windings of a wye-wye
transformer. Compute the processed current vectors to obtain the
“dashed” values for that winding.
Z Calculate the CT correction factor for windings 2 (and 3 if applicable)
and apply as necessary.
Z Turn the equations around to compute the threshold differential currents
in terms of the applied currents.
Note
Z To check the threshold without performing computations, inject
balanced 3-phase currents into any winding.
With balanced conditions, there is no effect on magnitude due to phase
shifting and zero-sequence removal has no effect. However, the CT ratio
mismatch is still applicable.
Z Repeat the minimum pickup level measurements for the Phase B (inputs
H2 and G2) and the Phase C element (inputs H3 and G3).
The above tests have effectively verified the minimum operating level of the three
harmonic restrained differential elements. If desired the above measurements may be
repeated for the phase inputs for the other winding(s). The results should be identical.
7.5.2.3 Verification of Local Reset Mode
Z Set the differential element with a latched target.
Z Apply enough current to cause the relay to operate, then remove the
current.
The Trip LED and the Phase LED should be latched on.
Z Set S1 745 SETUP ZV RESETTING Z LOCAL RESET BLOCK to Disabled.
Z Press the RESET key. The target should reset.
Z Set S1 745 SETUP ZV RESETTING Z LOCAL RESET BLOCK to Logic
Input 1(16).
Z Press the RESET key and verify that the target does not reset if the
logic input is not asserted.
Z Verify the status of selected logic input through the A1 STATUS ZV
LOGIC INPUTS ZV LOGIC INPUT 1(16) STATE actual value.
Z Assert the selected logic input, apply the current to cause the target to
latch and verify that pressing the RESET button does not reset the LED.
The following message should appear: INVALID KEY: MUST BE IN LOCAL
MODE.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–17
COMMISSIONINGCHAPTER 7: COMMISSIONING
7.5.2.4 Verification of Remote Reset Mode
Z Set the differential element with a latched target.
Z Apply enough current to cause the relay to operate, then remove the
current.
The Trip LED and the Phase LED should be latched on.
Z Set S1 745 SETUP ZV RESETTING ZV REMOTE RESET SIGNAL to Logic
Input 1(16).
Z Assert logic input 1.
The target should reset.
7.5.2.5 Verification of Solid-state Output
If the solid-state Output Is Used To Drive Auxiliary Relays,
Z Verify that these relays operate whenever the relay is in a trip condition.
Z Ensure that the current though the auxiliary coils is interrupted by an
external contactor between each test.
To avoid operating the breaker during the commissioning process when the solid-state
output operates the breaker directly,
Z Use the circuit shown below to verify this output.
Whenever the relay is in a trip state, current flows through the load
resistor.
Z Select the resistor for approximately 1 × CT of DC current with the
normal DC supply voltage used in your relay scheme.
FIGURE 7–4: Solid-state output test circuit
7.5.2.6 Basic Operating Time
To measure the basic operating time of the harmonic restrained differential elements,
Z Connect an AC current signal to terminals H1 and G1, through a
double-pole single-throw switch.
The second pole of the switch starts a timer circuit which is stopped by
the operation of the relay trip contact. Refer to the figure below for
details.
Z Close the switch and set the current level to three (3) times the minimum
pickup value measured earlier.
7–18
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
Z Re-open the switch and reset all targets on the relay.
Z Ensure that timer circuit functions correctly.
Z Close the switch and record operating time of relay.
FIGURE 7–5: Timer test circuit
7.5.2.7 Slope Measurements
The auto configuration processes the currents to correct for phase shifts, CT mismatch,
and zero sequence component removal. As such, it more complex to measure the slope
from an external single phase injection. Therefore, the use of displayed actual values is
recommended.
The differential and restraint currents are displayed the A2 METERING Z CURRENT ZV
DIFFERENTIAL Z PHASE A DIFFERENTIAL CURRENT and A2 METERING ZV CURRENT ZV
RESTRAINT Z PHASE A RESTRAINT CURRENT actual values:
To measure the slope,
Z Connect current signals to the relay as shown in the figure below:
FIGURE 7–6: Current signal connections
If I1 = 1.5 × CT and I2 = 0, the element is operated as all the current appears as a differential
current.
The slope is calculated from the values of Idifferential and Irestraint as follows:
I differential
%slope = ------------------------- × 100%
I restraint
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–19
COMMISSIONINGCHAPTER 7: COMMISSIONING
Z Slowly increase I2. As I2 is increased, the element will reset when the
differential current drops below the minimum pickup.
As I2 continues to increase, the element operates again when both the initial slope and the
minimum pickup conditions are satisfied.
Z Calculate the initial slope 1 value at this point.
As I2 increases further, the element may reset again, depending on the setting of the slope
kneepoint. This is caused by the current values moving into the slope 2 region.
Z Continue increasing I2 until the element operates again.
Z Compute the slope 2 value at this point.
7.5.2.8 Slope Kneepoint
Z To measure the approximate kneepoint location, follow the procedure
above, setting I1 equal to the kneepoint.
Z Gradually increase I2 until the element resets.
Z Calculate the first slope at this point.
This value should be equal to the initial slope setting.
Z Increase I2 until the element operates again.
Z Calculate the slope at this point.
It should be equal to the final slope.
If the kneepoint is much different than the selected value of I1, the two
values of slope will be the same.
Z For an accurate measurement of the kneepoint, select a value of I1 just
above the kneepoint value.
Z Increase I2 until the element resets.
Z Calculate the slope.
The value should be equal to the initial slope value.
Z Increase I1 by a small amount, say 10%, and adjust I2 until a new
operating point is obtained.
Z Calculate the slope.
Z Repeat until the slope value equals the final slope.
The kneepoint value is the value of the restraint current at which the
slope changed in value.
Note
Keep in mind the effects of auto-configuration on the magnitude of the current signal fed
to the differential elements when conducting the slope kneepoint test.
7.5.2.9 Second Harmonic Restraint
To measure the percentage of second harmonic required to block the operation of the
harmonic-restraint differential elements, use the connection diagram shown below.
Current is supplied as an operating current to the phase A element.
7–20
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
FIGURE 7–7: Second harmonic restraint testing
Z Close switch S1. Set the AC current, IAC to 2 × rated CT secondary. Set
IDC to obtain harmonic content above the 2nd harmonic restraint setting
under S4 ELEMENTS ZV DIFFERENTIAL ZV HARMONIC INHIBIT ZV
HARMONIC INHIBIT LEVEL.
Z Calculate the percent second harmonic content from the following
equations. If the current is measured with average-responding/reading
meters:
Z
100 × 0.424 × I DC
%2nd = -----------------------------------------I DC + 0.9 × I AC
Z If the current is measured with RMS-responding/reading meters, then:
100 × 0.424 × I
I DC + 1.414 × I AC
DC
Z %2nd = ------------------------------------------
Z Open and reclose S1. The relay should not operate.
Z Decrease IDC until the element operates. Calculate the percent of second
harmonic at this point using the equations above. The calculated percent
harmonic value should equal the relay setting.
7.5.2.10 Fifth Harmonic Restraint
Verifying the operation of the 5th harmonic restraint requires test equipment capable of
generating a current signal containing a fundamental and 5th harmonic. Most modern
dedicated relay test instruments, such as Powertec's (or Manta) DFR, Doble, or MultiAmp
instruments are capable of generating appropriate signals. A power operational amplifier
with a suitably rated output, or a power audio amplifier, may also be used to generate the
appropriate signal.
Z Connect the test setup as below to supply the phase A element. Set the
fundamental current level to the CT rated secondary value. The
harmonic restraint differential element of phase A should be operated.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–21
COMMISSIONINGCHAPTER 7: COMMISSIONING
FIGURE 7–8: Fifth harmonic restraint testing
Z Increase the 5th harmonic component to a value well above the S4
ELEMENTS ZV DIFFERENTIAL ZV 5th HARM INHIBIT ZV 5th
HARMONIC INHIBIT LEVEL setting.
Z Remove the total current signal and reapply.
The relay should not operate.
Z Decrease the 5th harmonic component until the element operates.
Z Calculate the percentage 5th harmonic to restrain from the following
equation:
× level of 5th harmonic%5th = 100
-------------------------------------------------------------------level of fundamental
Z Compare this value to the relay setting.
7.5.2.11 Energization Detection Scheme
Refer to Differential Element on page 5–48 for a description of this feature. This feature is
activated by up to three inputs: breaker auxiliary switch, current below a threshold, or
absence of voltage. The procedure below tests the current-level enabling feature. A similar
approach can verify the other two enabling functions with the proper test equipment.
Z Enable the Energization Detection Scheme by setting S4 ELEMENTS ZV
DIFFERENTIAL ZV ENERGIZATION INHIBIT Z ENERGIZATION INHIBIT
FUNCTION to Enabled.
Z Make the following setpoint changes in the S4 ELEMENTS ZV
DIFFERENTIAL ZV ENERGIZATION INHIBIT setpoints menu:
ENERGIZATION INHIBIT PARMETERS: “2nd”
HARMONIC AVERAGING: “Disabled”
ENERGIZATION INHIBIT LEVEL: “15%”
ENERGIZATION INHIBIT DURATION: “5 s”
ENERGIZATION SENSING BY CURRENT: “Enabled”
ENERGIZATION INHIBIT/MINIMUM ENERGIZATION CURRENT: “0.10
× CT”
Z Preset current with harmonic content just above the ENERGIZATION
INHIBIT LEVEL used during the ‘energization period’.
7–22
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
Z Apply the current signal and measure the operating time.
The time should be equal to ‘energization period’ plus approximately 50
ms.
Z Disable the energization detection scheme and repeat the timing test.
The operate time should be the normal operating time of harmonic
restraint differential element.
7.5.2.12 Target, Output, Contact, And Display Operation
Z Verify the correct operation of all targets, output contacts, and display
messages during the percent differential tests above.
7.5.2.13 Blocking from Logic Inputs
Each element can be programmed to be blocked by a logic input, virtual input, virtual
output, output relay operation, or self-test relay operation. This procedure verifies that the
differential element is blockable by logic input 1.
Z Select logic input 1 by setting the S4 ELEMENTS ZV DIFFERENTIAL Z
PERCENT DIFFERENTIAL ZV PERCENT DIFFERENTIAL BLOCK setpoint
to Logc Inpt 1.
Z Apply current to operate the differential element then assert logic input
1.
Z Verify that the element has reset and that all targets can be reset.
Z With logic input 1 asserted, remove the current and reapply.
Z Verify that the element did not operate.
7.5.3
Instantaneous Differential Protection
7.5.3.1 Overview
Settings for this element are under the S4 ELEMENTS ZV INST DIFFERENTIAL setpoints
group. All other protective elements must be disabled to ensure that trip relay(s) and
auxiliary relays are operated by element under test. Monitor the appropriate contact per
intended settings of the FlexLogic™.
7.5.3.2 Minimum Pickup
The operating level of the phase A element is measured by applying an AC current to
terminals H1 and G1. Monitor the appropriate trip and auxiliary contact(s) as the current is
increased from 0 A. Due to the auto-configuration feature, it may be easier to read the
actual differential current on the relay rather computing it.
Z Compare the value of the differential current at which operation is
detected against the S4 ELEMENTS ZV INST DIFFERENTIAL ZV INST
DIFFERENTIAL PICKUP setpoint.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–23
COMMISSIONINGCHAPTER 7: COMMISSIONING
Z Check that the Trip and Message LEDs are flashing and the following
trip message is displayed:
LATCHED a (bc) Inst Differential.
Note
The message may show OPERATED instead of LATCHED if the TARGET setpoint is “SelfReset”.
7.5.3.3 Operating Time
To measure the basic operating time of the instantaneous differential elements,
Z Connect an AC current signal to terminals H1 and G1 through a doublepole, single-throw switch.
The second pole of the switch starts a timer circuit that will be stopped
by the operation of the relay trip contact. Refer to FIGURE 7–5: Timer
test circuit on page 7–19.
Z Close the switch and set the current level to two times the pickup value
measured earlier.
Z Re-open the switch and reset all targets on the relay.
Z Ensure that the timer circuit functions correctly.
Z Close the switch and record operating time of relay.
Note
All differential currents are calculated using the same principal shown in Transformer
Type Selection on page 7–11. The differential current derivation is affected by phase
shift compensation and zero sequence removal.
7.5.3.4 Target, Output Contact, and Display Operation
Z Verify the correct operation of all targets and output contacts and
display messages during testing.
7.5.3.5 Blocking from Logic Inputs
Each element is programmable to be blocked by a logic input, virtual input, virtual output,
output relay operation, or self-test relay operation. This test verifies that the differential
element can be blocked by logic input 1.
Z Select Logic Input 1 by setting the S4 ELEMENTS ZV DIFFERENTIAL Z
PERCENT DIFFERENTIAL ZV PERCENT DIFFERENTIAL BLOCK setpoint
to Logc Inpt 1.
Z Apply current to operate the differential element then assert logic input
1.
Z Verify that the element has reset and that all targets can be reset.
Z With logic input 1 asserted, remove the current and reapply.
Z Verify that the element did not operate.
7–24
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
7.5.4
Phase Time Overcurrent
7.5.4.1 Description
This procedure verifies that the phase time overcurrent element performance matches the
in-service settings. Since these elements can have any one of a multitude of timing curves,
a table of expected operating times versus applied current should be prepared prior to
testing the elements. Refer to Time Overcurrent Curves on page 5–58 for information on
timing curves.
If the relay elements are set for a “Linear” reset characteristic when measuring the
operating times, ensure that there is sufficient time between test current injections for the
element to reset fully; otherwise, erroneous timing measurements will be obtained. The
settings for these elements are found in the S4 ELEMENTS ZV PHASE OVERCURRENT
setpoints page.
7.5.4.2 Winding 1 Elements
To ensure that only the phase time overcurrent elements operate the trip relays (and any
other output relays) selected by the logic, disable all protection features except phase time
overcurrent. Use the general test setup shown below:
FIGURE 7–9: General test setup
Connect the current supply to terminals X = H1 and Y = G1 to test the winding 1 phase A
element. Monitor the appropriate output relays per the FlexLogic™ settings or from
assigned relay settings from Phase TOC.
7.5.4.3 Pickup Level
Z With the interval timer disabled, apply the current signal and increase its
magnitude slowly until the trip relay and all the selected auxiliary relays
operate.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–25
COMMISSIONINGCHAPTER 7: COMMISSIONING
If the element has a very inverse time characteristic, it is easier and more accurate to
increase the current far above the pickup level until the trip relay operates then reduce the
current to just above the operate level. Then, current can be slowly reduced below the
operate level and observed for a reset action on the trip relay. This reset level for the
current should be approximately 98% of the pickup level.
Z Once the relay drops out, slowly increase the current until the trip
contact closes.
The operate level should correspond to the pickup setting.
Z Check that one of the following messages is displayed:
LATCHED a: W1 Phase Time OC or OPERATED a: W1 Phase
Time OC
The message will indicate LATCHED or OPERATED, depending on the setting for the target.
7.5.4.4 Operating Time
Using a table like the one shown below, select three (3) or four (4) values of current
multiples at which the timing is to be measured.
Z Enter the expected operating times from the timing curve applied in the
settings.
Z Using the setup shown in FIGURE 7–9: General test setup on page 7–
25 and the Interval Timer enabled, set the current level to the desired
value.
Z Apply suddenly by closing the double-pole switch.
Z Record the operating time.
Z Compare this to the expected value.
Z Repeat for all desired values of current.
Current multiple
Nominal time
Measured time
1.5
3
5
7.5.4.5 Reset Time
A precise measurement of the reset time requires a relay test set capable of dynamic
operation, with three sequenced stages, each with programmable current levels and time
duration external contact, and flexible triggering. To perform such a test, please contact
GE Multilin for detailed test instructions.
A simple verification the selected reset mode can be obtained using FIGURE 7–9: General
test setup on page 7–25. The procedure consists of performing repetitive operating time
measurements in quick succession. If the reset is selected for instantaneous, the operating
time will always be equal to the nominal time derived from the selected curve. If the reset is
selected as linear, the operating time will vary as a function of the time between successive
application of the current signal. If performed at current multiples of 2 to 3 times the
pickup level, the variations in operating time will be easier to detect.
7–26
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
7.5.4.6 Phase B and C Elements
If the Phase A element performed correctly and met specifications, repeat the pickup level
portion of the above test for the B and C phases of winding 1. For Phase B, X = H2 and
Y = G2. For phase C, X = H3 and Y = G3. The displayed message should change to indicate
the correct phase, winding, and element that operated.
7.5.4.7 Winding 2 and 3 Elements
Because the winding 2 and 3 elements can be set with completely different parameters
than the elements for winding 1, it is necessary to repeat the full set of tests described
above for each winding.
The blocking from logic input, if enabled, can be tested as described in earlier tests for
other elements.
Note
7.5.5
Phase Instantaneous Overcurrent 1
7.5.5.1 Description
This procedure verifies that the phase instantaneous overcurrent performance matches
the in-service settings. The settings for these elements are found under the S4 ELEMENTS
ZV PHASE OVERCURRENT setpoints menu. The testing occurs at current multiples of at
least five times the rated CT secondary value. Do not leave the current signal on for more
than a few seconds!
7.5.5.2 Winding 1 elements
To ensure that only the phase instantaneous overcurrent 1 element operates the trip
relays (and any other output relays) selected by the logic, disable all protection features
except phase instantaneous overcurrent 1. Use the general test setup shown in FIGURE 7–
9: General test setup on page 7–25.
Connect the current supply to terminals X = H1 and Y = G1 to test the winding 1 phase A
element. Monitor the appropriate output relays as per the relay FlexLogic™ settings or
assigned output relays from Phase IOC settings.
7.5.5.3 Pickup level
Z With the interval timer disabled, apply the current signal and increase its
magnitude until the trip relay (and all selected auxiliary relays) operate.
Z Compare the measured operating level against the S4 ELEMENTS ZV
PHASE OC ZV W1 PHASE INST OC 1 ZV W1 PHASE INST OC 1 PICKUP
setpoint.
Z Check that Trip, Pickup, and Phase A(C) LEDs turn on when the
element operates.
Z Check that one of the following messages is displayed:
LATCHED a: W1 Phase Inst OC 1 or OPERATED a: W1 Phase Inst
OC 1
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–27
COMMISSIONINGCHAPTER 7: COMMISSIONING
Z Reduce the current until the element resets.
The reset level should be 97% of the operate level. When the element
resets, the Trip and Phase LEDs should remain on if the W1 PHASE INST
OC 1 TARGET was selected as Latched. Otherwise, only the Trip LED
should stay on.
Z Reset indicators and clear messages.
7.5.5.4 Operating Time
Z Using the setup shown in FIGURE 7–9: General test setup on page 7–
25 and the Interval Timer enabled, set the current level to 1.5 times the
operating level of the element.
Z Apply current suddenly by closing the double-pole switch.
Z Record the operate time and compare it to the S4 ELEMENTS ZV PHASE
OC ZV W1 PHASE INST OC 1 ZV W1 PHASE INST OC 1 DELAY setpoint
value.
7.5.5.5 Phase B and C Elements
If the phase A element performed correctly and met specifications, repeat the pickup level
portion of the above test for phases B and C of winding 1. For phase B, X = H2 and Y = G2.
For phase C, X = H3 and Y = G3. The displayed message should change to indicate the
correct phase, winding, and element that operated.
7.5.5.6 Winding 2 and 3 elements
Because the winding 2 and 3 elements can be set with completely different parameters
than the winding 1 elements, it is necessary to repeat the full set of tests described above
for each winding.
7.5.6
Phase Instantaneous Overcurrent 2
The phase instantaneous overcurrent 2 elements are identical to the phase instantaneous
overcurrent 1 elements. As such, the same test procedure can be used to verify their
correct operation. Disable all protection features except the phase instantaneous
overcurrent 2 elements and follow the steps in the previous section, making the
appropriate changes for the display indications and output relays which are operated by
the phase instantaneous overcurrent 2 elements.
Note
7–28
The blocking from logic input, if enabled, can be tested as described in earlier tests for
other elements.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
7.5.7
Neutral Time Overcurrent
7.5.7.1 Description
This procedure verifies that the neutral time overcurrent performance matches the inservice settings. Since these elements can have any one of a multitude of timing curves, a
table of expected operating times versus applied current should be prepared prior to
testing. The neutral element measures the derived zero-sequence current signal as an
input. Refer to Time Overcurrent Curves on page 5–58 for information on timing curves.
If the relay elements are set for the “Linear” reset characteristic when measuring the
operating times, ensure there is sufficient time between test current injections for the
element to reset fully. Otherwise, erroneous timing measurements will be obtained.
The settings for these elements are found under the S4 ELEMENTS ZV NEUTRAL OC
setpoints menu. Note that there can only be one or two Neutral Time Overcurrent
elements in service at the same time.
7.5.7.2 Winding 1 Element
To ensure that only the neutral time overcurrent element under test operates the trip
relays (and any other output relays) selected by the logic, disable all protection features
except neutral time overcurrent. Use the general test setup shown in FIGURE 7–9: General
test setup on page 7–25.
Connect the current supply to terminals X = H1 and Y = G1 to test the winding 1 neutral
element. Monitor the appropriate output relays as per the relay FlexLogic™ settings or
assigned relays from phase IOC2 page.
7.5.7.3 Pickup Level
Z With the interval timer disabled, apply the current signal and slowly
increase its magnitude until the trip relay (and all the selected auxiliary
relays) operate.
If the relay under test has a very inverse time characteristic, it is easier and more accurate
to increase the current far above the pickup level until the trip relay operates, then reduce
the current to just above the expected operate level.
Z Slowly reduce the current below the operate level and observe for a
reset action on the trip relay.
This current reset level should be approximately 98% of the pickup
level setting. Once the relay drops out, slowly increase the current until
the trip contact closes. The operate level should correspond to the S4
ELEMENTS ZV NEUTRAL OC Z W1 NTRL TIME OC ZV W1 NEUTRAL
TIME OC PICKUP setpoint: Since current is being introduced into one
phase only, the input current signal is equal to the 3Io signal used by the
element.
Z When the element operates, check that the Trip, Pickup, and Phase
LEDs are on and one of the following messages is displayed:
LATCHED a: W1 Ntrl Time OC or OPERATED a: W1 Ntrl Time OC
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–29
COMMISSIONINGCHAPTER 7: COMMISSIONING
Z Reduce the current until the element resets.
The reset level should be 97% of the operate level. When the element
resets, the Trip and Message LEDs should remain on if the W1
NEUTRAL TIME OC TARGET was selected as Latched. Otherwise only
the Trip LED remains on.
Z Reset indicators and clear messages.
7.5.7.4 Operating Time
Z Using a table like the one shown below, select three (3) or four (4)
values of current multiples at which timing is to be measured.
Z Enter the expected operating times from the timing curve applied in the
settings.
Z Using the setup in FIGURE 7–9: General test setup on page 7–25 and
the interval timer enabled, set the current level to the desired value and
apply suddenly by closing the double-pole switch.
Z Record the operate time and compare to the expected value.
Z Repeat for all desired values of current.
Current multiple
Nominal time
Measured time
1.5
3
5
7.5.7.5 Reset Time
A precise measurement of the reset time requires a relay test set capable of dynamic
operation, with three sequenced stages, each with programmable current levels and time
duration, and flexible external contact triggering. To perform such a test, contact GE
Multilin for detailed test instructions.
A simple verification of the reset mode selected by S4 ELEMENTS ZV NEUTRAL OC Z W1
NTRL TIME OC ZV W1 NEUTRAL TIME OC RESET is obtained using the setup shown in
FIGURE 7–9: General test setup on page 7–25. The test consists of repetitive operating time
measurements in quick succession. If the reset is set for “Instantaneous”, the operating
time is always equal to the nominal time derived from the selected curve. If the reset is set
as “Linear”, the operating time varies as a function of the time between successive
applications of current. The variations in operating time are easier to detect if this test is
performed at current multiples of 2 to 3 times the pickup level.
7.5.7.6 Winding 2 or 3 Elements
Since the winding 2 and 3 elements can be set with completely different parameters than
the winding 1 elements, it is necessary to repeat the full set of tests described above for
each winding.
Z To test winding 2 elements, disable all protection elements except for
W2 NEUTRAL TIME OVERCURRENT.
7–30
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
Z Connect the current signal to X = H4 and Y = G4 and repeat tests in this
section.
Z To test winding 3 elements, disable all protection elements except for
W3 NEUTRAL TIME OVERCURRENT.
Z Connect the current signal to X = H7 and Y = G7 and repeat the tests in
this section.
The blocking from logic input, if enabled, can be tested as described in earlier tests for
other elements.
Note
7.5.8
Neutral Instantaneous Overcurrent 1
7.5.8.1 Description
This procedure verifies that the neutral instantaneous overcurrent performance is as per
the in-service settings. Settings for these elements are found under the S4 ELEMENTS ZV
NEUTRAL OC ZV W1 NTRL INST OC 1 setpoints menu. If the relay settings require testing at
current multiples of several times the rated CT secondary value, do not leave the current
signal on for more than a few seconds.
7.5.8.2 Winding 1 Element
To ensure that only the neutral instantaneous overcurrent 1 element operates the trip
relays (and any other output relays) selected by the logic,
Z Disable all protection features except neutral instantaneous overcurrent
1. Use the general test setup shown in FIGURE 7–9: General test setup
on page 7–25.
Z Connect the current supply to terminals X = H1 and Y = G1 to test the
winding 1 phase A element.
Z Monitor the appropriate output relays as per the relay FlexLogic™
settings or assigned relay settings.
7.5.8.3 Pickup level
Z With the interval timer disabled, apply the current signal and increase its
magnitude until the trip relays (and all the selected auxiliary relays)
operate.
Z Compare the measured operating level against the S4 ELEMENTS ZV
NEUTRAL OC ZV W1 NTRL INST OC 1 ZV W1 NEUTRAL INST OC 1
PICKUP value.
Z Check that, when the element operates, the Trip and Pickup LEDs are on
and one of the following messages is displayed:
LATCHED a: W1 Ntrl Inst OC 1 or OPERATED a: W1 Ntrl Inst OC
1
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–31
COMMISSIONINGCHAPTER 7: COMMISSIONING
Z Reduce the current until the element resets.
The reset level should be 97% of the operate level. When the element
resets, the Trip and Message LEDs should remain on if the W1
NEUTRAL INST OC 1 TARGET was selected as “Latched”. Otherwise only
the Trip LED should stay on.
Z Reset indicators and clear messages.
7.5.8.4 Operating Time
Z With the setup shown in FIGURE 7–9: General test setup on page 7–25
and the interval timer enabled, set the current level to 1.5 times the
operate level of the element and apply suddenly by closing the doublepole switch.
Z Record the operate time and compare to the S4 ELEMENTS ZV NEUTRAL
OC ZV W1 NTRL INST OC 1 ZV W1 NEUTRAL INST OC 1 DELAY value.
7.5.8.5 Winding 2 and 3 elements
Because the winding 2 and 3 elements can be set with completely different parameters
than the winding 1 elements, it is necessary to repeat the full set of tests described in this
section for each winding.
Only two neutral instantaneous overcurrent 1 elements can be in service
simultaneously.
Note
The blocking from logic input, if enabled, can be tested as described in earlier tests for
other elements.
Note
7.5.9
Neutral Instantaneous Overcurrent 2
The neutral instantaneous overcurrent 2 elements are identical to the neutral
instantaneous overcurrent 1 elements. Consequently, the same test procedure can be
used to verify their correct operation. Disable all protection features except neutral
instantaneous overcurrent 2 and follow the steps in the previous section, making the
appropriate changes for the LEDs and output relays operated by the neutral instantaneous
overcurrent 2 elements.
7.5.10 Ground Time Overcurrent
7.5.10.1 Description
This procedure verifies that the ground time overcurrent performance matches the inservice settings. Since these elements can be assigned a multitude of timing curves, a
table of expected operating times versus applied current should be prepared prior to
testing. The ground element measures the current signal connected to the ground current
7–32
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
input CT, H10 and G10 or F12 and E12. Refer to Time Overcurrent Curves on page 5–58 for
information on timing curves. There can only be one or two ground time overcurrent
elements in service at the same time.
If the relay elements are set for the “Linear” reset characteristic when measuring the
operating times, ensure there is sufficient time between test current injections for the
element to reset fully. Otherwise, erroneous timing measurements will be obtained. The
settings for these elements will be found under the S4 ELEMENTS ZV GROUND OC Z W1
GND TIME OC setpoints menu.
7.5.10.2 Winding 1 Element
To ensure that only the ground time overcurrent element operates the trip relays (and any
other output relays) selected by the logic,
Z Disable all protection features except ground time overcurrent.
Use the general test setup shown in FIGURE 7–9: General test setup on
page 7–25.
Z Connect the current supply to terminals X = H10 and Y = G10 to test
the winding 1 ground element.
Z Monitor the appropriate output relays as per the relay FlexLogic™
settings or assigned relay settings.
7.5.10.3 Pickup Level
Z With the interval timer disabled, apply the current signal and slowly
increase its magnitude until the trip relay (and all the selected auxiliary
relays) operate.
If the relay has a very inverse time characteristic, it is easier and more accurate to increase
the current far above the pickup level until the trip relay operates and then reduce the
current to just above the operate level. Then slowly reduce the current below the operate
level and observe for a reset action on the trip relay. This reset level for the current should
be approximately 98% of the pickup level. Once the relay drops out, slowly increase the
current until the trip contact closes. The operate level should correspond to the S4
ELEMENTS ZV GROUND OC Z W1 GND TIME OC ZV W1 GROUND TIME OC PICKUP setpoint.
Z When the element operates, check that the Trip, Ground, and Pickup
LEDs are on and one of the following messages is displayed:
LATCHED a: W1 Gnd Time OC or OPERATED a: W1 Gnd Time
OC
Z Reduce the current until the element resets.
The reset level should be 97% of the operate level. When the element
resets the Trip and Message LEDs should remain on if the W1 GROUND
TIME OC TARGET was selected as Latched. Otherwise, only the Trip
LED should remain on.
Z Reset indicators and clear messages.
7.5.10.4 Operating Time
Using a table like the one shown blow,
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–33
COMMISSIONINGCHAPTER 7: COMMISSIONING
Z Select three (3) or four (4) values of current multiples at which the
timing is to be measured.
Z Enter the expected operating times from the timing curve applied in the
settings.
Z Using FIGURE 7–9: General test setup on page 7–25 with the interval
timer enabled, set the current level to the desired value and apply
suddenly by closing the double-pole switch.
Z Record the operate time and compare to the expected value.
Z Repeat for the all the desired values of current.
Current multiple
Nominal time
Measured time
1.5
3
5
7.5.10.5 Reset Time
A precise measurement of the reset time requires a relay test set capable of dynamic
operation, with three sequenced stages, each with programmable current levels and time
duration, and flexible external contact triggering. To perform such a test, contact GEGE
Multilin for detailed test instructions.
A simple verification of the reset mode selected with the S4 ELEMENTS ZV GROUND OC Z
W1 GND TIME OC ZV W1 GROUND TIME OC RESET setpoint is obtained using the setup in
FIGURE 7–9: General test setup on page 7–25. The procedure consists of repetitive
operating time measurements in quick succession. If the reset is selected for
“Instantaneous”, the operating time always equals the nominal time derived from the
selected curve. If the reset is selected as “Linear”, the operating time varies as a function of
the time between successive applications of the current signal. If this test is performed at
current multiples of 2 to 3 times the pickup level, the variations in operating time are easier
to detect.
7.5.10.6 Winding 2 or 3 elements
Because the second ground time overcurrent element could be set with completely
different parameters than the element for the first winding, it is necessary to repeat the full
set of tests described above for each winding.
To test the second element,
Z Disable all protection elements except for the W2 GROUND TIME
OVERCURRENT (or W3 GROUND TIME OVERCURRENT) element.
Z Connect the current signal to X = F12 and Y = E12.
Z Repeat all the tests described for the winding 1 ground time overcurrent
element in this section.
Note
7–34
The blocking from logic input, if enabled, can be tested as described in earlier tests for
other elements.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
7.5.11 Ground Instantaneous Overcurrent 1
7.5.11.1 Description
This procedure verifies that the ground instantaneous overcurrent performance matches
the in-service settings. Settings for these elements are found under the S4 ELEMENTS ZV
GROUND OC ZV W1 GND INST OC 1 setpoints menu. If your relay settings require you to
test at current multiples of several times the rated CT secondary value do not leave the
current signal on for more than a few seconds.
7.5.11.2 Winding 1 Element
To ensure only the ground instantaneous overcurrent 1 element operates the trip relays
(and any other output relays) selected by the logic, disable all protection features except
ground instantaneous overcurrent 1. Use the test setup shown in FIGURE 7–9: General test
setup on page 7–25.
Connect the current supply to terminals X = H10 and Y = G10 to test the winding 1
element. Monitor the appropriate output relays as per the relay FlexLogic™ settings or
assigned relay settings.
7.5.11.3 Pickup Level
Z With the interval timer disabled, apply the current signal and increase its
magnitude until the trip relay (and all the selected auxiliary relays)
operate.
Z Compare the measured operating level against the S4 ELEMENTS ZV
GROUND OC ZV W1 GND INST OC 1 ZV W1 GND INST OC 1 PICKUP
setpoint.
Z When the element operates, check that the Trip and Message LEDs are
flashing and one of the following messages is displayed:
LATCHED a: W1 Gnd Inst OC 1 or OPERATED a: W1 Gnd Inst OC
1
Z Reduce the current until the element resets.
The reset level should be 97% of the operate level. When the element
resets the Trip, Ground, and Message LEDs should remain on if the W1
GND INST OC 1 TARGET was selected as “Latched”. Otherwise, only the
Trip LED should stay on.
Z Reset indicators and clear messages.
7.5.11.4 Operating Time
Using the setup shown in FIGURE 7–9: General test setup on page 7–25 with the Interval
Timer enabled,
Z Set the current level to 1.5 times the element operate level and apply
suddenly by closing the double-pole switch.
Z Record the operate time and compare to the S4 ELEMENTS ZV GROUND
OC ZV W1 GND INST OC 1 ZV W1 GND INST OC 1 DELAY value.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–35
COMMISSIONINGCHAPTER 7: COMMISSIONING
7.5.11.5 Winding 2 or 3 Element
Because the winding 2 and 3 elements can be set with completely different parameters
than the winding 1 elements, it is necessary to repeat the full set of tests described in this
section for each winding.
Note
Note
Only two ground instantaneous overcurrent 1 elements can be in service
simultaneously.
The blocking from logic input, if enabled, can be tested as described in earlier tests for
other elements.
7.5.12 Ground Instantaneous Overcurrent 2
The ground instantaneous overcurrent 2 elements are identical to the ground
instantaneous overcurrent 1 elements. Consequently, the same test procedure may be
used to verify their correct operation. Disable all protection features except ground
instantaneous overcurrent 2. Make the appropriate changes for the display indications
and output relays operated by the ground instantaneous overcurrent 2 elements.
7.5.13 Restricted Ground Fault Polarity Test
This procedure verifies the correct wiring of field CTs (phase and ground) to the
corresponding phase and ground CT terminals on the relay for the purposes of the
restricted ground fault protection. The correct wiring is determined by the distribution of
fault current during external phase A to ground faults on wye-connected windings with
grounded neutral.
From the figure below, the If fault current travels through the wye-grounded neutral as Ig
and can be simulated by injecting a single current into the phase A (W2) and G1/2
terminals.
Phase A CT(W2)
RGF polarity wiring test
*
*
I1
If
G4
Phase A (W2)
H4 *
745 relay
H4 *
Ig
G4
3I0
If = I1
AC source
50/60 Hz signal
G1/2 input
H10 *
H10 *
G10
Ig
*
*
G10
Ig = I2
If = Ig = I1 = I2
I3Io – Ig I = 0
I2
Ground CT
FIGURE 7–10: Fault current distribution due to an external phase-to-ground fault on winding 2
7–36
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
The procedure for this test is shown below:
Z Select the D/Y30° transformer type into the relay and set the same CT
ratio for both phase and ground winding inputs.
The selected transformer type assures the G1/2 ground input is
associated to winding 2 (wye).
Z Enable the restricted ground fault protection only and monitor the
ground differential current under the relay actual values.
Z Connect the single current source to inject current into G10 of the
ground G1/2 terminal and to the connected in-series winding 2 phase A
terminals as shown on the figure above.
Z Verify the ground current and phase A current are in phase
Z Verify the ground differential current is zero
Note
The polarities and wirings of the CTs for the restricted ground fault protection are correct if
the external phase-to-ground fault current is seen on both relay terminals (phase and
ground) in the same direction. The response of the restricted ground fault protection is
based on the magnitude of the ground differential current resulting from the vector
difference of the neutral and ground currents; that is, I gd = 3I 0 – I g .
7.5.14 Restricted Ground Fault Element Test
7.5.14.1 Description
This procedure verifies that the restricted ground fault performance matches the inservice settings. The ground element measures the current signal connected to the ground
current input CT, H10 and G10 or F12 and E12. The neutral (3Io) current is calculated from
the vector sum of the three phase currents. Injecting current into one phase automatically
produces a neutral current (i.e. 3Io = IA). Settings for these elements are found in the S4
ELEMENTS ZV RESTRICTED GROUND ZV W1(3) RESTD GND FAULT setpoints menu.
7.5.14.2 Winding 1 Element
To ensure that only the restricted ground fault element operates the trip relays (and any
other output relays selected by the logic) disable all protection features except restricted
ground fault.
Using a current supply as shown in the figure below, connect the I1 current source to
terminals H1 and G1 for the winding 1 phase current element and I2 to terminals G10 and
H10 as shown for the ground current element. Monitor the appropriate output relays as
per the relay FlexLogic™ settings or assigned relay settings.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–37
COMMISSIONINGCHAPTER 7: COMMISSIONING
FIGURE 7–11: Restricted ground test setup
7.5.14.3 Pickup Level
Z With the interval timer disabled, apply the current signal feeding the
phase current element and increase its magnitude slowly until the trip
relay, and all the selected auxiliary relays, operate.
The operate level should correspond to the S4 ELEMENTS ZV
RESTRICTED GROUND Z W1 RESTD GND FAULT ZV W1 RESTD GND
FAULT PICKUP setting.
Z When the element operates, check that the Trip, Ground, and Pickup
LEDs are on and that one of the following messages is displayed:
LATCHED a: W1 Restd Gnd Fault or OPERATED a: W1 Restd
Gnd Fault
Z Reduce the current until the element resets.
The reset level should be 97% of the operate level. When the element
resets, the Trip and Message LEDs should remain on if the W1 RESTD
GND FAULT TARGET was selected as Latched. Otherwise, only the Trip
LED should remain on.
Z Reset indicators and clear messages.
7.5.14.4 Operating Time
Z Select three (3) or four (4) delay times at which the timing is to be
measured.
Z With the interval timer enabled, set the current level to the desired value
and apply suddenly by closing the double-pole switch.
Z Record the operate time and compare to the expected value.
Z Repeat for the all the desired values of current.
7.5.14.5 Slope
Z To measure the slope, connect current signals to the relay as shown in
the figure above.
7–38
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
Z Inject the I1 current such that the ground differential pickup value
divided by the I1 current is less than the slope setting. Set I2 = 0 A.
The element will operate since the current appears as ground
differential.
Z The slope is calculated from the values of Iground differential and Imax as
shown below:
I ground differential
%slope = ------------------------------------------ × 100%
I max
(EQ 7.11)
where Imax represents the maximum phase current for the
winding being measured.
As I2 is increased, the element will reset when the percentage of
slope drops below the slope setting.
Z Slowly increase I2 until the element operates again.
Z Calculate the slope at this point.
Z Decrease the slope setting to 0% then continue to increase the I2 current
until the element resets.
Z Slowly increase I2 until the element operates again.
The reset level should be 97% of operate level. When the element resets, the Trip and
Message LEDs should remain on if the W1 RESTD GND FAULT TARGET was selected as
“Latched”. Otherwise only the Trip LED should remain on.
7.5.14.6 Winding 2 or 3 Elements
Since the second restricted ground fault element can be set with completely different
parameters than the first element winding, it is necessary to repeat the full set of tests
described in this section for each winding.
To test the second element,
Z Disable all protection elements except for the winding 2 (or winding 3
as appropriate) restricted ground fault element.
Z Connect the ground current signal to terminals F12 and E12.
Z Repeat all the tests described for the winding 1 element in this section.
Note
The blocking from logic input, if enabled, can be tested as described in earlier tests for
other elements.
7.5.15 Negative-sequence Time Overcurrent
7.5.15.1 Description
This procedure verifies that the negative-sequence time overcurrent performance
matches the in-service settings. Since these elements can have any one of a multitude of
timing curves, a table of expected operating times versus applied current should be
prepared prior to testing the elements. The negative-sequence element measures the
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–39
COMMISSIONINGCHAPTER 7: COMMISSIONING
derived negative-sequence component of the phase current signals connected to the
phase input CTs. Refer to Time Overcurrent Curves on page 5–58 for additional information
on timing curves.
If the relay elements are set for “Linear” reset characteristic when measuring the operating
times, ensure that there is sufficient time between test current injections for the element to
reset fully. Otherwise, erroneous timing measurements will be obtained. Settings for these
elements are found in the S4 ELEMENTS ZV NEG SEQ OC Z W1 NEG SEQ TIME OC settings
menu.
7.5.15.2 Winding 1 Element
To ensure that only the negative-sequence time overcurrent element operates the trip
relays (and any other output relays selected by the logic),
Z Disable all protection features except negative-sequence time
overcurrent.
Z Use the general test setup shown in FIGURE 7–9: General test setup on
page 7–25.
Z Connect the current supply to terminals X = H1 and Y = G1 to test the
winding 1 negative-sequence element.
Z Monitor the appropriate output relays as per the relay FlexLogic™
settings or assigned relay settings.
7.5.15.3 Pickup Level
Z With the interval timer disabled, apply the current signal and slowly
increase its magnitude until the trip relay and all selected auxiliary
relays operate.
If the relay has a very inverse time characteristic, it is easier and more
accurate to increase the current far above the pickup level until the trip
relay operates then reduce the current to just above the operate level.
Z Slowly reduce the current below the operate level and observe for a
reset action on the trip relay.
This reset level for the current should be approximately 98% of the
pickup level.
Z Once the relay drops out, slowly increase the current until the trip
contact closes. The operate level should correspond to the S4 ELEMENTS
ZV NEG SEQ OC Z W1 NEG SEQ TIME OC ZV W1 NEG SEQ TIME OC
PICKUP setting.
Note
With current applied to a single phase, the negative sequence current component is
calculated from:
1
I neg seq = --- × I phase
3
(EQ 7.12)
Hence, the phase current will be three times the pickup setting.
Z Check that, when the element operates, the Trip and Pickup LEDs are
on, and one of the following messages is displayed:
7–40
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
LATCHED a: W1 Neg Seq Time OC or OPERATED a: W1 Neg Seq
Time OC
Z Reduce the current until the element resets.
The reset level should be 97% of the operate level. When the element
resets the Trip and Message LEDs should remain on if the W1 NEG SEQ
TIME OC TARGET was selected as Latched. Otherwise only the Trip
LED remains on.
Z Reset indicators and clear messages.
7.5.15.4 Operating Time
Z Using a table like the one shown below, select 3 or 4 values of current
multiples at which the timing is to be measured.
Z Enter the expected operating times from the timing curve applied in the
settings.
Z Using the setup in FIGURE 7–9: General test setup on page 7–25 with
the interval timer enabled, set the current level to the desired value
(taking into account the relationship mentioned above) and apply
suddenly by closing the double-pole switch.
Z Record the operate time and compare to the expected value.
Z Repeat for all desired values of current.
Current multiple
Nominal time
Measured time
1.5
3
5
7.5.15.5 Reset time
A simple verification of which reset mode, selected with the S4 ELEMENTS ZV NEG SEQ OC
Z W1 NEG SEQ TIME OC ZV W1 NEG SEQ TIME OC RESET setpoint, can be obtained using
the simple test setup in FIGURE 7–9: General test setup on page 7–25. The procedure
consists of repetitive operating time measurements in quick succession. If the reset is
selected for “Instantaneous”, the operating time is always equal to the nominal time
derived from the selected curve. If the reset is selected as Linear, the operating time varies
as a function of the time between successive applications of the current signal. If this test
is performed at current multiples of 2 to 3 times the pickup level, the variations in operating
time are easier to detect.
7.5.15.6 Winding 2 and 3 Elements
Because the negative-sequence time overcurrent elements on windings 2 and/or 3 can be
set with completely different parameters than those for the first element, it is necessary to
repeat the full set of tests described in this section for each winding.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–41
COMMISSIONINGCHAPTER 7: COMMISSIONING
To test these elements, disable all protection elements except for winding 2 negativesequence time overcurrent. Connect the current signal to X = H4 and Y = G4. Repeat all the
tests described for the winding 1 element in this section. For winding 3, connect the
current signal to X = H7 and Y = G7.
Note
The blocking from logic input, if enabled, can be tested as described in earlier tests for
other elements.
7.5.16 Negative-sequence Instantaneous Overcurrent
7.5.16.1 Description
This procedure verifies that the negative-sequence instantaneous overcurrent
performance matches the in-service settings. These elements are found under the S4
ELEMENTS ZV NEG SEQ OC ZV W1 NEG SEQ INST OC settings menu. If the relay settings
require testing at current multiples of several times the rated CT secondary value, do not
leave the current signal on for more than a few seconds.
7.5.16.2 Winding 1 element
To ensure that only the Negative Sequence Instantaneous Overcurrent element operates
the trip relays (and any other output relays selected by the logic),
Z Disable all protection features except Negative Sequence Instantaneous
Overcurrent.
Z Use the general test setup in FIGURE 7–9: General test setup on page
7–25.
Z Connect the current supply to terminals X = H1 and Y = G1 to test the
Winding 1 element.
Z Monitor the appropriate output relays as per the relay FlexLogic™
settings.
7.5.16.3 Pickup Level
Z With the interval timer disabled, apply the current signal and increase its
magnitude until the trip relay and all selected auxiliary relays operate.
Z Compare the measured operating level against the S4 ELEMENTS ZV
NEG SEQ OC ZV W1 NEG SEQ INST OC ZV W1 NEG SEQ INST OC
PICKUP relay settings.
Note
With current applied to a single phase, the negative sequence current component is
calculated from:
1
I neg seq = --- × I phase
3
(EQ 7.13)
Hence, the phase current will be three times the pickup setting.
Z When the element operates, check that the Trip and Pickup LEDs are on
and one of the following is displayed:
7–42
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
LATCHED a: W1 Neg Seq Inst OC or OPERATED a: W1 Neg Seq
Inst OC
Z Reduce the current until the element resets.
The reset level should be 97% of the operate level. When the element
resets, the Trip and Message LEDs should remain on if the W1 NEG SEQ
INST OC TARGET was selected as Latched. Otherwise, only the Trip
LED should remain on.
Z Reset indicators and clear messages.
7.5.16.4 Operating Time
Z Using the setup in General test setup on page 7–25 with the Interval
Timer enabled, set the current level to 1.5 times the operate level of the
element and apply suddenly by closing the double-pole switch.
Z Record the operate time and compare to the S4 ELEMENTS ZV NEG SEQ
OC ZV W1 NEG SEQ INST OC ZV W1 NEG SEQ INST OC DELAY setting.
7.5.16.5 Winding 2 and 3 Elements
Because the winding 2 and 3 elements can be set with completely different parameters
than the element for winding 1,
Z Repeat the full set of tests described for the winding 1 element in this
section.
Z Connect the current supply to terminals X = H4 and Y = G4 to test the
Winding 2 element. Use X = H7 and Y = G7 for the Winding 3 element.
The blocking from logic input, if enabled, can be tested as described in earlier tests for
other elements.
Note
7.5.17 Frequency
7.5.17.1 Setup
The power system frequency is measured from the voltage input if it has been enabled. If
there is no voltage input, it is measured from the winding 1 phase A current signal. These
tests require a variable-frequency current source for relays without a voltage input and a
variable-frequency voltage and current source for relays with a voltage input. Connections
are shown in the figure below. Only perform tests specific to the relay model.
Note
The underfrequency, overfrequency, and frequency decay elements are all supervised by
optional adjustable minimum current and minimum voltage level detectors. When testing
the performance of these elements on a 745 with the voltage input enabled, it may be
necessary to inject a current signal into winding 1 phase A if the current supervision is
enabled, or else the detectors will not operate.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–43
COMMISSIONINGCHAPTER 7: COMMISSIONING
FIGURE 7–12: Frequency element testing
7.5.17.2 Underfrequency 1
As a preliminary step, disable all protection functions except underfrequency 1. Verify that
settings match the in-service requirements. Settings are entered or modified in the S4
ELEMENTS ZV FREQUENCY Z UNDERFREQUENCY 1 settings menu.
Voltage input function (voltage input enabled):
Z Using the variable-frequency voltage/current source connected to
terminals C11 and C12 for the voltage signal and H1 and G1 for the
current signal, set the frequency to 60.00 Hz (or 50.00 Hz for 50 Hz
systems) and the voltage amplitude to the rated VT secondary voltage.
Z Set the current amplitude to rated CT secondary.
Z Monitor the appropriate trip and auxiliary relays.
Z Reset all alarms and indications on the relay.
The relay display should remain with no trip indications.
Z Slowly decrease the frequency until the output relay(s) operate.
Z Check that the operation took place at the selected frequency setting.
Z As the frequency is varies, verify that the correct system frequency is
displayed by the A2 METERING ZV FREQUENCY Z SYSTEM
FREQUENCY actual value.
Z Slowly reduce the voltage and note the voltage at which the output
relay(s) reset.
Z Check that this dropout voltage is approximately the voltage supervision
value in the S4 ELEMENTS ZV FREQUENCY Z UNDERFREQUENCY 1
ZV MINIMUM OPERATING VOLTAGE setpoint.
Note
If voltage supervision is set to 0.0, then the element remains operated until the voltage is
decreased below approximately 2%, the level at which measurements become unreliable.
Z Slowly increase the voltage and check that the element operates when
the voltage reaches 2% above the supervision level.
Z Return the voltage to nominal value.
Z Slowly decrease the current until the element resets.
7–44
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
Z Check that this dropout current level is equal to the S4 ELEMENTS ZV
FREQUENCY Z UNDERFREQUENCY 1 ZV MINIMUM OPERATING
CURRENT setting:
Note
If current sensing is disabled in the element, it will remain operated with current reduced to
0.0 A.
Z Slowly increase the current and ensure the element operates when the
current reaches a value just above the setting. Set the current to rated CT
secondary.
Z Check that the Trip and Pickup LEDs are on and one of the following
trip messages is displayed:
LATCHED: Underfrequency 1 or OPERATED: Underfrequency 1
Z Slowly increase the frequency until the Pickup LED and output relays
reset. Note the dropout level, which should be the pickup plus 0.03 Hz.
Z Check that the Trip LED is still on.
The trip message will stay on if the UNDERFREQUENCY 1 TARGET
setting is “Latched”; if set to “Self-resetting”, the message will reset
when frequency is above the setpoint.
For timing tests, the signal generator must be capable of triggering into step-wise
changing of frequency or ramping down to a pre-selected frequency in only a few
milliseconds.
Z Connect the Signal Source and Timer Start triggers as shown in
FIGURE 7–12: Frequency element testing on page 7–44.
Z Set the voltage to rated VT secondary value, the current to rated CT
secondary, and the pre-trigger frequency to the nominal frequency (60
or 50 Hz).
If current sensing is not enabled, it is not necessary to connect the
current signal.
Z Set the post-trigger to 0.5 Hz below the setting for underfrequency 1.
Reset all targets and relays, if necessary.
Z Reset the timer.
Z Initiate the frequency step and timer start.
The Interval Timer will record the operating time of element. Compare
this time to the S4 ELEMENTS ZV FREQUENCY Z UNDERFREQUENCY 1
ZV UNDERFREQUENCY 1 DELAY setpoint value:
Provided that the operate times are not scattered over a wide range, it may be desirable to
repeat this test several times and average the results. If there is a wide scatter, verify the
test setup and ensure the signal source behaves in a consistent manner.
Current input function (voltage input disabled):
Z If the frequency elements are using the winding 1 phase A current signal
as a source, verify the operation of the element using the instructions
below.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–45
COMMISSIONINGCHAPTER 7: COMMISSIONING
Z Using the variable-frequency current source connected to terminals H1
and G1 with no voltage connections, set the frequency to 60.00 Hz (or
50.00 Hz) and the amplitude to the rated CT secondary current.
Z Monitor the appropriate trip and auxiliary relays.
Z Reset all alarms and indications.
The display should remain unchanged with no trip indications.
Z Slowly decrease the frequency until the output relay(s) operate.
Check that the frequency at which operation took place is the selected
frequency setting.
Z Slowly reduce the current.
Z Note the current at which the output relay(s) reset.
Z Check that this dropout current is the minimum operating current
selected in the settings.
Note
If current sensing is not enabled, then the element will continue working all the way
down to a current level of 0.02 × CT A.
Z Increase the current back to nominal. Verify that the relay(s) operate.
Z Check that the Trip and Pickup LEDs are on and one of the following
trip messages is displayed:
LATCHED: Underfrequency 1 or OPERATED: Underfrequency 1
Z Slowly increase the frequency until the Pickup LED and output relays
reset.
Z Note the dropout level, which should be the pickup plus 0.03 Hz.
Z Check that the Trip LED is still on.
The trip message remains on if the UNDERFREQUENCY 1 TARGET
setting is Latched; if set to “Self-Resetting”, the message resets when
frequency is above the setpoint.
For timing tests, the signal generator must be capable of triggering into step-wise
changing of frequency or ramping down to a pre-selected frequency in only a few
milliseconds.
Z Connect the signal source and timer start triggers as shown in FIGURE
7–12: Frequency element testing on page 7–44.
Z Set the current to rated CT secondary value, no voltage connection, and
the pre-trigger frequency to the nominal frequency (60 or 50 Hz).
Z Set the post-trigger to 0.5 Hz below the underfrequency 1 setting.
If necessary, reset all targets and relays.
Z Reset the timer.
Z Initiate the frequency step and timer start.
The Interval Timer will record the operating time of element.
Z Compare this time to the S4 ELEMENTS ZV FREQUENCY Z
UNDERFREQUENCY 1 ZV UNDERFREQUENCY 1 DELAY setting.
7–46
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
Z Provided that the operate times are not scattered over a wide range, it
may be desirable to repeat this test several times and average the results.
Z If there is a wide scatter, verify the test setup and ensure the signal
source behaves in a consistent manner.
Note
The blocking from logic input, if enabled, can be tested as described in earlier tests for
other elements.
7.5.17.3 Underfrequency 2
Z Disable all protection functions except the underfrequency 2 function.
Z Verify that settings match in-service requirements. Enter/modify
settings and logic in the S4 ELEMENTS ZV FREQUENCY ZV
UNDERFREQUENCY 2 setpoints menu.
Z Repeat the appropriate steps of Underfrequency 1 on page 7–44 for this
element.
Z Compare the results to the settings for the underfrequency 2 element.
7.5.17.4 Overfrequency
Z Disable all protection functions except overfrequency.
Z Verify that settings match in-service requirements.
Overfrequency settings are modified in the S4 ELEMENTS ZV
FREQUENCY ZV OVERFREQUENCY settings menu.
Voltage input function (voltage input enabled):
Using the variable-frequency voltage/current source connected to terminals C11 and C12
for the voltage signal and H1 and G1 for the current signal,
Z Set the frequency to 60.00 Hz (or 50.00 Hz) and the voltage amplitude
to the rated VT secondary voltage.
Z Set the current amplitude to rated CT secondary.
Z Monitor the appropriate trip and auxiliary relays.
Z Reset all alarms and indications on the relay.
The 745 display should remain unchanged with no trip indications.
Z Slowly increase the frequency until the output relay(s) operate.
Z Check that the frequency at which operation took place is the selected
frequency setting.
Z As the frequency is varied, verify that the A2 METERING ZV
FREQUENCY Z SYSTEM FREQUENCY actual value indicates the correct
value of system frequency.
Z Slowly reduce the voltage.
Z Note the voltage at which the output relay(s) reset.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–47
COMMISSIONINGCHAPTER 7: COMMISSIONING
Z Check that this dropout voltage is equal to the S4 ELEMENTS ZV
FREQUENCY ZV OVERFREQUENCY ZV MINIMUM OPERATING
VOLTAGE voltage level.
Note that this level can be set down to 0.00 A, in which case the element
remains operated to a voltage level of approximately 2% of nominal.
Z Slowly increase the voltage and check that the element operates when
the voltage reaches 2% above the set level.
Z Return the voltage to nominal value.
Z Slowly decrease the current until the element resets.
Z Check that this dropout current level is equal to the S4 ELEMENTS ZV
FREQUENCY ZV OVERFREQUENCY ZV MINIMUM OPERATING
CURRENT setting.
If current sensing has not been enabled for this element, the element
remains operated for current levels down to 0.00 A.
Z Slowly increase the current and check that the element operates when
the current reaches a value just above the setting.
Z Set the current to rated CT secondary.
Z Check that the Trip and Pickup LEDs are on and one of the following
trip messages is displayed:
LATCHED: Overfrequency or OPERATED: Overfrequency
Z Slowly decrease the frequency until the Pickup LED and output relays
reset.
Z Note the dropout level, which should be the pickup minus 0.03 Hz.
Check that the Trip LED is still on.
The trip message remains on if the OVERFREQUENCY TARGET setting is
“Latched”; if set to “Self-resetting”, the message resets when frequency
is below the setpoint.
For timing tests, the signal generator must be capable of triggering into step-wise
changing of frequency or ramping down to a pre-selected frequency in only a few
milliseconds.
Z Connect the signal source and timer start triggers as shown in FIGURE
7–12: Frequency element testing on page 7–44.
Z Set the voltage to rated VT secondary value, the current to rated CT
secondary, and the pre-trigger frequency to nominal frequency (60 or 50
Hz).
The current signal is not required if current sensing is not enabled for
this element.
Z Set the post-trigger to 0.5 Hz above the setting of the overfrequency
element. If necessary, reset all targets and relays.
Z Reset the timer.
Z Initiate the frequency step and timer start.
The interval timer records the operating time of element.
7–48
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
Z Compare this time to the S4 ELEMENTS ZV FREQUENCY ZV
OVERFREQUENCY DELAY setting.
Provided that the operate times are not scattered over a wide range, it may be desirable to
repeat this test several times and average the results.
If there is a wide scatter, verify the test setup and ensure the signal source behaves in a
consistent manner.
Current input function (voltage input disabled):
If the voltage input is disabled, the frequency elements use the winding 1 phase A current
signal as a source. Verify the operation of the element using the procedure below.
Z Using the variable-frequency current source connected to terminals H1
and G1, no voltage connections, frequency at 60.00 Hz (or 50.00 Hz),
and the amplitude to rated CT secondary current.
Z Monitor the appropriate trip and auxiliary relays.
Z Reset all relay alarms and indications.
The relay display should remain unchanged with no trip indications.
Z Slowly increase the frequency until the output relay(s) operate.
Z Check that the frequency at which operation took place is the selected
frequency setting.
Z Slowly reduce the current.
Z Note the current at which the output relay(s) reset.
Z Check that this dropout current is the minimum operating current
selected in the settings.
If current sensing has been disabled for this element, then operation
continues down to 0.00 A.
Z Increase the current back to nominal.
Z Check that the relay(s) operate.
Z Check that the Trip and Pickup LEDs are on and one of the following
trip messages is displayed:
LATCHED: Overfrequency or OPERATED: Overfrequency
Z Slowly decrease the frequency until the Pickup LED turns on and output
relays reset.
Z Note the dropout level, which should be the pickup minus 0.03 Hz.
Z Check that the Trip LED is still on.
The trip message stays on if the OVERFREQUENCY TARGET setting is
Latched; if it is Self-resetting, the message resets when frequency is
below the setpoint.
Z For timing tests, the signal generator must be capable of triggering into
step-wise changing of frequency or ramping down to a pre-selected
frequency in only a few milliseconds.
Z Connect the signal source and timer start triggers as shown in FIGURE
7–12: Frequency element testing on page 7–44.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–49
COMMISSIONINGCHAPTER 7: COMMISSIONING
Z Set the current to rated CT secondary value, no voltage connection, and
the pre-trigger frequency to the nominal frequency (60 or 50 Hz).
Z Set the post-trigger to 0.5 Hz above the setting of the Overfrequency
element.
Z Reset all targets and relays, if necessary.
Z Reset the timer.
Z Initiate the frequency step and timer start.
The Interval Timer records the element operating time.
Z Compare this time to the S4 ELEMENTS ZV FREQUENCY ZV
OVERFREQUENCY ZV OVERFREQUENCY DELAY setting:
Provided that the operate times are not scattered over a wide range, it may be desirable to
repeat this test several times and average the results.
If there is a wide scatter, verify the test setup and ensure the signal source behaves in a
consistent manner.
Note
The blocking from logic input, if enabled, can be tested as described in earlier tests for
other elements.
7.5.17.5 Frequency Decay Rate
Note
A high-quality programmable function generator is required to verify this element. Since
the frequency rates of change are measured over a narrow range, the test
instrumentation must accurately simulate frequency decay rates without any significant
jitter. It is the experience of GE Multilin that some commercial dedicated relay test
equipment with built-in frequency ramping functions is not accurate enough to verify the
745 performance.
Z Disable all protection functions except the Frequency Decay function.
Z Verify that settings match in-service requirements.
The settings are entered and modified in the S4 ELEMENTS ZV
FREQUENCY ZV FREQUENCY DECAY setpoints menu.
The following procedures are for the frequency decay rate 1 element. They can be applied
to the frequency decay rate 2, 3, and 4 elements as well, making the necessary changes
where appropriate.
Voltage input function (voltage input enabled):
Z Use a frequency-ramping programmable voltage/current source
connected to terminals C11 and C12 for the voltage signal and H1 and
G1 for the current signal.
Z Set the frequency to 60.00 Hz (or 50.00 Hz) and the voltage amplitude
to the rated VT secondary voltage.
Z Set the current amplitude to rated CT secondary (Note: if current
sensing is disabled for this element, the current signal is not required for
the tests).
Z Monitor the appropriate trip and auxiliary relays.
7–50
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
Z Reset all alarms and indications on the relay.
The relay display should remain unchanged with no trip indications.
Z Program the function generator to simulate a frequency rate-of-change
just above rate 1.
The start frequency should be the nominal frequency of the relay; the
end frequency must be below the frequency decay threshold if the relay
is to operate. Note that operation occurs if the rate criterion is satisfied
and the frequency is below the threshold.
Z Initiate ramping action and verify element operation once the frequency
drops below the threshold.
Z Check that the Trip and Pickup LEDs are on and one of the following
trip messages is displayed:
LATCHED: Freq Decay Rate 1 or OPERATED: Freq Decay Rate 1
If the target was selected as Latched, the Trip LED and the
message remain on.
Z Reduce the voltage to below the S4 ELEMENTS ZV FREQUENCY ZV
FREQUENCY DECAY ZV MINIMUM OPERATING VOLTAGE voltage
supervision level.
Z Repeat ramping action and verify that element does not operate.
If the voltage supervision level has been set to 0.00, the element
continues to operate correctly down to approximately 2% or nominal.
Z Return voltage to nominal value.
Z If current sensing is enabled, set the current level below the S4
ELEMENTS ZV FREQUENCY ZV FREQUENCY DECAY ZV MINIMUM
OPERATING CURRENT value.
Z Repeat ramping action and verify that element does not operate.
Z For timing tests, an approximate operate time is obtained if a timer is
triggered at the same time as the ramping action and the time interval
between the trigger point and the relay operation measured.
From that measured time, subtract the time required for the frequency to
reach the threshold value.
Current input function (voltage input disabled):
Z Using a frequency-ramping programmable voltage/current source
connected to terminals H1 and G1 for the current signal, set the
frequency to 60.00 Hz (or 50Hz). Set the current amplitude to rated CT
secondary.
Z Monitor the appropriate trip and auxiliary relays.
Z Reset all alarms and indications on the relay.
The relay display should remain unchanged with no trip indications.
Z Program the function generator to simulate a frequency rate-of-change
just above rate 1.
The start frequency should be the nominal frequency of the relay. The
end frequency must be below the frequency decay threshold if the relay
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–51
COMMISSIONINGCHAPTER 7: COMMISSIONING
is to operate.
Note that operation occurs if the rate criterion is satisfied and the
frequency is below the threshold.
Z Initiate ramping action and verify that the element operates once the
frequency drops below the threshold.
Z Check that the Trip and Pickup LEDs are on and one of the following
trip messages is displayed:
LATCHED: Freq Decay Rate 1 or OPERATED: Freq Decay Rate 1
If the target was selected as Latched, the Trip LED and the
message remain on.
Z Set the current level to a value below the S4 ELEMENTS ZV FREQUENCY
ZV FREQUENCY DECAY ZV MINIMUM OPERATING CURRENT value.
Z Repeat ramping action and verify that element does not operate.
If current sensing has been disabled for this element, operation will
continue down to a current level of approximately 2% of nominal.
Z For timing tests, an approximate operate time is obtained if a timer is
triggered at the same time as the ramping action and the time interval
between the trigger point and the relay operation measured.
Z From that measured time, subtract the time required for the frequency to
reach the threshold value.
The expected time must be computed using the rate of change and the
effect of the S4 ELEMENTS ZV FREQUENCY ZV FREQUENCY DECAY
ZV FREQUENCY DECAY DELAY time delay.
7.5.18 Overexcitation
7.5.18.1 Volts per Hertz
The following procedure applies to both volts-per-hertz elements; make the necessary
changes where appropriate. The volts-per-hertz operating levels are set in terms of the
relay-input voltage divided by the frequency of that voltage.
Z Disable all elements except volts-per-hertz 1.
Z Monitor the appropriate contact.
Z Use the test setup in FIGURE 7–12: Frequency element testing on page
7–44 with variable-frequency voltage source.
The Volts-per-hertz settings are found in the S4 ELEMENTS ZV OVEREXCITATION Z VOLTSPER-HERTZ 1 setpoints menu.
Z Apply a voltage starting at 60 Hz and increase the magnitude until the
element operates.
Z Reduce the frequency in steps of 5 Hz and repeat the measurement.
The element should operate at a consistent value of volts/hertz equal to
the setting of the element.
Z Check that the Trip and Pickup LEDs are on and one of the following
trip messages is displayed:
7–52
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
LATCHED: Volts-Per-Hertz 1 or OPERATED: Volts-Per-Hertz 1
Z For timing tests, prepare a table of expected operating time versus
applied V/Hz signal from the selected timing curve for the element.
Z Using the variable frequency function generator to simulate the different
V/Hz ratios, apply suddenly to the relay and measure the operating time.
7.5.18.2 Fifth Harmonic Scheme
The 5th harmonic scheme operates if the 5th harmonic content of any current signal
connected to the relay exceeds the threshold setting, for the set time, provided that the
level is above the set threshold.
Z Disable all protection functions except the 5th harmonic function.
The 5th harmonic scheme settings are in the S4 ELEMENTS ZV
OVEREXCITATION ZV 5th HARMONIC LEVEL setpoints menu.
This test requires a current generator capable of producing a fundamental and 5th
harmonic component.
Z Connect the current signal to H1 and G1 and set the fundamental
component level above the threshold setting.
Z Slowly increase the amplitude of the 5th harmonic component until the
element operates.
Z Calculate the ratio of 5th harmonic to fundamental at which operation
occurred and compare this value to the setting of the element.
Z Check that the Trip, Pickup (and if selected, Alarm) LEDs are on, and
one of the following is displayed:
LATCHED: 5th Harmonic Level or OPERATED: 5th Harmonic
Level
Z Reduce the 5th harmonic component until the element resets.
The reset level should be 97% of the operate level.
Z Reset indicators and clear messages.
Z Repeat the above steps with a fundamental current level below the
threshold setting.
Z Ensure that the element does not operate.
Z For timing tests, simulate an operating condition as above and apply
suddenly to the relay and measure the operating time.
The time should be the same as the setting in the element.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–53
COMMISSIONINGCHAPTER 7: COMMISSIONING
7.5.19 Insulation Aging
7.5.19.1 Description
The three elements under the insulation aging feature, hottest-spot limit, aging factor limit,
and loss of life limit, must be tested with a valid set of transformer data programmed into
the relay. The ambient temperature must also be programmed (obtained from an RTD or
programmed as 12-month averages). The tests consist of simulating transformer loading
by applying a current signal to winding 1 phase A at the correct frequency.
7.5.19.2 Hottest-spot Limit
The hottest-spot temperature value is a function of load, ambient temperature, and
transformer rating.
Z Apply a current to winding 1 phase A to represent at least a 100% load
on the transformer.
Z Use the A2 METERING ZV LOSS OF LIFE Z HOTTEST-SPOT
WINDING TEMPERATURE actual value to observe the hottest spot
temperature increases gradually. The simulated load to may be increased
for a faster temperature rise.
When the hottest spot temperature reaches the S4 ELEMENTS ZV INSULATION AGING Z
HOTTEST-SPOT LIMIT ZV HOTTEST-SPOT LIMIT PICKUP operating level, the element should
operate.
Z Verify all programmed relay operations as per FlexLogic™ settings.
Z Verify that all the targets and messages are as expected and
programmed.
The time delay can be verified with a watch as the delay is normally set in minutes.
7.5.19.3 Aging Factor Limit
The Aging Factor value is also a function of load, ambient temperature, and transformer
ratings.
Z Apply a current to Winding 1 Phase A to represent at least a 100%
transformer load.
Z Use the A2 METERING ZV LOSS OF LIFE ZV INSULATION AGING
FACTOR actual value to observe that the aging factor increases
gradually.
Z You may want to increase the simulated load or the simulated or
programmed ambient temperature to cause a faster increase.
When the aging factor reaches the S4 ELEMENTS ZV INSULATION AGING ZV AGING
FACTOR LIMIT ZV AGING FACTOR LIMIT PICKUP operating level, the element should
operate.
Z Verify all programmed relay operations as per FlexLogic™ settings.
Z Verify that all the targets and messages are as expected and
programmed.
The time delay can be verified with a watch as the delay is normally set in minutes.
7–54
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
7.5.19.4 Loss of Life Limit
Typical settings for the loss-of-life limit element dictate that either the limit be changed or
the initial transformer loss-of-life be changed temporarily. Verification of this function is
recommended by programming an initial loss-of-life above the element threshold. The
element operates instantly as it has no associated time delay.
7.5.20 Tap Monitor Failure
The tap monitor failure element operates when the sensed resistance is 150% larger than
the programmed values for the monitor circuit.
Z Connect a resistance to simulate the tap changer resistance and increase
this resistance until the element operates.
Z Calculate that the resistance at which the element operated is 150% of
the resistance that would be present at the maximum tap position.
Z Verify all relay, targets and messages for correct operation per
programmed values.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–55
COMMISSIONINGCHAPTER 7: COMMISSIONING
7.6
Auxiliary protection and monitoring functions
7.6.1
THD Level Scheme
7.6.1.1 Minimum Pickup
Testing of this element uses with the same setup used in testing the harmonic restraint
percent differential elements (see FIGURE 7–1: Test setup on page 7–4).
To test the winding 1 THD element,
Z Connect the composite current signal to terminals H1 and G1.
Since the DC component actually consists of a half-wave rectified
signal, it contains all even harmonics which the relay measures and
operates on.
Note that the fundamental component is required to prevent saturation
of the input CTs. Monitor the output relays as per the relay FlexLogic™
assignment.
Z Set the fundamental component to rated CT secondary (1 or 5 A).
Z Gradually increase the DC component to produce even harmonics until
the THD level element operates.
Z Display the total harmonic content under A2 METERING ZV
HARMONIC CONTENT ZV THD Z W1 THDa (2nd-21st).
The displayed value of THD at which operation took place should be the
same as the programmed value.
Z Check that the Trip, Pickup (and Alarm if selected) LEDs are on and
one of the following is displayed:
LATCHED: W1 THD Level or OPERATED: W1 THD Level
Z Lower the DC component until the element resets.
The reset value should be approximately 2% less than the operate value.
Z Verify that the Phase, Pickup, and Alarm LEDs reset if the target
function is set to Self-resetting.
The Trip LED should remain latched.
7.6.1.2 Operating time
To measure the basic operating time of this element,
Z Preset a fundamental and DC component composite current signal to
cause the element to operate.
Z Using the setup of Figure 10-1, apply the current suddenly, at the same
time as you trigger the timer.
The measured operating time should correspond to the time delay
setting for the element.
7–56
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
7.6.1.3 Minimum Operating Current
The THD elements will only operate if the amplitude of the fundamental component is
above the threshold setting.
To verify this threshold,
Z Initially set the fundamental component above the threshold, with a
harmonic content high enough to cause the element to operate.
Z Now reduce the fundamental component only.
This will have the effect of increasing the THD level. When the
fundamental component reaches a value below the set threshold, the
element will reset.
If an RMS-responding meter is used to measure the current signal, the reading is the
total value of current. To determine the fundamental component only, use the relay
values in A2 METERING Z CURRENT Z W1 CURRENT. These values represent the
fundamental component only.
7.6.1.4 Other THD Elements
A THD element can be programmed for each winding of the transformer. Use the above
procedures to verify the element(s) on the other winding(s).
7.6.2
Harmonic Derating Function
Testing of the harmonic derating function requires that accurate transformer parameters
such as load losses at rated load and winding resistance be entered. This feature makes
use of the harmonic derating factor (HDF) computed by the relay, using the harmonic
content of the current signals and the transformer data (refer to IEEE C57.110-1986 for the
computation method). Once the derating factor falls below a set value, the 745 can trip
and/or alarm.
7.6.2.1 Operating level
To verify the correct operation of this element, a current signal containing harmonics must
be introduced into one phase of the relay. Use FIGURE 7–1: Test setup on page 7–4 to
accomplish this.
Z Set the fundamental component at rated CT secondary into winding 1
phase A.
Z Gradually increase the second harmonic component (and the rest of the
even harmonics) while displaying the A2 METERING ZV HARMONIC
CONTENT ZV HARMONIC DERATING ZV W1(3) HARMONIC
DERATING FACTOR value.
The element should operate when the displayed HDF equals the element
setting.
Z Check that the Trip, Pickup (and Alarm if selected) LEDs are on, and
one of the following is displayed:
LATCHED: W1 Harm Derating or OPERATED: W1 Harm
Derating
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–57
COMMISSIONINGCHAPTER 7: COMMISSIONING
Z Lower the DC component until the element resets.
The reset value should be approximately 2% larger than the operate
value.
Z Verify that the Pickup and Alarm LEDs reset if the target function is set
to Self-resetting.
The Trip LED should remain latched.
7.6.2.2 Operating Time
To measure the basic operating time of this element,
Z Preset a fundamental and DC component composite current signal to
cause the element to operate.
Z Using the setup of FIGURE 7–1: Test setup on page 7–4, apply the
current suddenly, at the same time the timer is triggered.
The measured operating time should correspond to the time delay
setting for the element.
7.6.3
Transformer Overload
The transformer overload element uses the phase A current of each winding to compute a
transformer loading. The computation assumes a rated voltage on the wInding, hence the
loading is effectively a percent of rated load current.
7.6.3.1 Operating Level
Z Inject a fundamental-frequency current into phase a of winding 1.
Z Increase the current signal to a value just above the transformer
overload pickup setting (take into account the CT ratio and the ratedMVA phase current to set the current correctly).
The element should operate after its set time delay.
Z Check that the Trip, Pickup (and Alarm if selected) LEDs are on, and
one of the following is displayed:
LATCHED: Xformer Overload or OPERATED: Xformer Overload
Z Lower the current until the element resets.
The reset value should be approximately 97% of the operate value.
Z Verify that the Pickup and Alarm LEDs reset if the target function is set
to Self-resetting.
The Trip LED should remain latched.
7–58
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: COMMISSIONINGCOMMISSIONING
7.6.3.2 Operating Time
Using the setup in Frequency element testing on page 7–44 with the interval timer enabled,
Z Set the current level to 1.5 times the operate level of the element and
apply suddenly by closing the double pole switch.
Z Record the operate time and compare to the S4 ELEMENTS ZV
XFORMER OVERLOAD ZV TRANSFORMER OVERLOAD DELAY setting.
Note
The blocking from logic input, if enabled, can be tested as described in earlier tests for
other elements.
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
7–59
COMMISSIONINGCHAPTER 7: COMMISSIONING
7.7
Placing the Relay into Service
7.7.1
Precautions
The procedure outlined in this section is explicitly concerned with the 745 relay and does
not include the operation/commissioning or placing into service of any equipment external
to the 745. Users should have already performed such tests as phasing of CTs, ratio
measurement, verification of saturation curve, insulation test, continuity and resistance
measurements.
7.7.2
Procedure
Z Restore all settings and logic to the desired in-service values.
Z Verify against the check list prepared while testing the relay.
Z Upload all the 745 setpoints to a computer file and print for a final
inspection to confirm that all setpoints are correct.
Z Set the 745 clock (date and time).
Z Clear all historical values stored in the relay by entering “Yes” at A3
EVENT RECORDER ZV EVENT DATA CLEAR Z CLEAR EVENT
RECORDER.
Z Remove all test connections, supplies, monitoring equipment from the
relay terminals and relay panels except for equipment to be used to
monitor first transformer energization.
Z Restore all panel wiring to normal except for those changes made
intentionally for the first energization (blocking of some tripping
functions for example).
Z Perform a complete visual inspection to confirm that the 745 is ready to
be placed into service.
Z Ensure that the relay is properly inserted in its case.
Z Energize the relay power supply and verify that the Relay In Service
LED is ON, and that the Self-Test Error LED is OFF, establishing that
the relay is operating normally.
7–60
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
GE Consumer & Industrial
Multilin
745 Transformer Protection
System
Appendix
Appendix
A.1
Change Notes
A.1.1
Revision History
Manual part no.
A.1.2
Revision
Release date
ECO
1601-0161-A1
3.0x
July 2, 2004
---
1601-0161-A2
3.0x
April 24, 2006
745-296
1601-0161-A3
5.0x
March 9, 2007
1601-0161-A4
5.1x
July 31, 2007
1601-0161-A5
5.1x
March 24, 2008
1601-0161-A6
5.1x
June 12, 2008
1601-0161-A7
5.1x
June 29, 2009
745-311
Changes to the 745 Manual
Table A–3: Major updates for 745 manual revision A7
Page (A5)
Page (A6)
Change
Description
Title
Title
Update
Manual part number to 1601-0161-A7
General
General
Update
Restructure page numbering
Table A–4: Major updates for 745 manual revision A6
Page (A5)
Page (A6)
Change
Description
Title
Title
Update
Manual part number to 1601-0161-A6
5-152
5-152
Update
Replace drawing 5-16
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
a–1
APPENDIX
Table A–5: Major updates for 745 manual revision A5
Page (A4)
Page (A5)
Change
Description
Title
Title
Update
Manual part number to 1601-0161-A5
2-16
2-16
Update
Change to DC Power Supply range - order table
Table A–6: Major updates for 745 manual revision A4
Page (A3)
Page (A4)
Change
Description
Title
Title
Update
Manual part number to 1601-0161-A4
3-10
3-36
Update
Changes to Typical Ground Input Connections table (table 3-2).
Ch 5
Ch 5
Addition
New Protection Element setting situated between "function"
and "target" on all Protection Element settings pages.
5-11
5-101
Update
Changes to Transformer Types table (table 5-1).
5-39
5-134
Update
Changes to "Introduction to Elements" section.
5-45
5-139
Update
Changes to fig 5-9
5-90
5-192
Update
Changes to fig 5-49
6-22
6-227
Update
Change to Flash Message "Input Function is Already Assigned"
7-7
7-239
Update
Change to Equation 7.1
Table A–7: Major updates for 745 manual revision A3
Page
(A2)
Page
(A3)
Change
Description
Title
Title
Update
Manual part number to 1601-0161-A3
2-9
2-9
Update
Changes to ELECTROSTATIC DISCHARGE values
Table A–8: Major updates for 745 manual revision A2
Page
(A1)
a–2
Page
(A2)
Change
Description
Title
Title
Update
Manual part number to 1601-0161-A2.
2-3
2-3
Update
Updated Ordering section
2-5
2-5
Update
Updated Protection elements specifications section
---
3-5
Add
Added Ethernet connection section
4-7
4-7
Update
Updated Hardware section
4-13
4-13
Update
Updated Configuring Ethernet communications section
5-25
5-24
Update
Updated Communications section
---
6-3
Add
Added Network status section
6-19
6-20
Update
Updated Self-test errors section
7-4
7-4
Update
Updated Dielectric strength testing section
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
APPENDIX
A.2
APPENDIX
EU Declaration of Conformity
A.2.1
EU Declaration
EU DECLARATION OF CONFORMITY
Applicable Council Directives:
73/23/EEC: The Low Voltage Directive
89/336/EEC: The EMC Directive
Standard(s) to Which Conformity is Declared:
IEC 947-1: Low Voltage Switchgear and Controlgear
IEC1010-1:1990+ A 1:1992+ A 2:1995 Safety Requirements for Electrical Equipment for
Measurement, Control, and Laboratory Use
CISPR 11 / EN 55011:1997:
EN 50082-2:1997
Class A – Industrial, Scientific, and Medical Equipment
Electromagnetic Compatibility Requirements, Part 2: Industrial
Environment
IEC100-4-3 / EN 61000-4-3: Immunity to Radiated RF
EN 61000-4-6: Immunity to Conducted RF
Manufacturer’s Name: General Electric Multilin Inc.
Manufacturer’s Address: 215 Anderson Ave.
Markham, Ontario, Canada
L6E 1B3
Manufacturer’s Representative in the EU: Christina Bataller Mauleon
GE Multilin
Avenida Pinoa 10
48710 Zamudio, Spain
Telephone: 34-94-4858835
Fax: 34-94-4858838
Type of Equipment: Protection and Control Relay
Model Number: 745
First Year of Manufacture: 1998
I the undersigned, hereby declare that the equipment specified above conforms to
the above Directives and Standards
Full Name: John Saunders
Position: Manufacturing Manager
Signature:
Place: GE Multilin
Date: 08/20/1998
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
a–3
APPENDIX
A.3
GE Multilin Warranty
A.3.1
Warranty Statement
General Electric Multilin (GE Multilin) warrants each device it manufactures to be free from
defects in material and workmanship under normal use and service for a period of 24
months from date of shipment from factory.
In the event of a failure covered by warranty, GE Multilin will undertake to repair or replace
the device providing the warrantor determined that it is defective and it is returned with all
transportation charges prepaid to an authorized service centre or the factory. Repairs or
replacement under warranty will be made without charge.
Warranty shall not apply to any device which has been subject to misuse, negligence,
accident, incorrect installation or use not in accordance with instructions nor any unit that
has been altered outside a GE Multilin authorized factory outlet.
GE Multilin is not liable for special, indirect or consequential damages or for loss of profit or
for expenses sustained as a result of a device malfunction, incorrect application or
adjustment.
For complete text of Warranty (including limitations and disclaimers), refer to GE Multilin
Standard Conditions of Sale.
a–4
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
INDEX
Index
Index
Numerics
2ND HARMONIC RESTRAINT .................................................................. 7-20, 7-21
5TH HARMONIC INHIBIT
setpoints .......................................................................................................... 5-56
5TH HARMONIC LEVEL
setpoints .......................................................................................................... 5-84
testing ............................................................................................................. 7-53
5TH HARMONIC RESTRAINT .................................................................. 7-21, 7-22
A
AGING FACTOR LIMIT
setpoints .......................................................................................................... 5-92
testing ............................................................................................................. 7-54
ALARM INDICATOR ........................................................................................... 4-3
AMBIENT TEMPERATURE ............................................................... 5-39, 7-13, 7-14
ANALOG INPUT
setpoints .......................................................................................................... 5-94
specifications ................................................................................................... 2-6
typical wiring ................................................................................................... 3-16
ANALOG OUTPUTS
commissioning ........................................................................................ 7-14, 7-15
connection ....................................................................................................... 3-17
setpoints ............................................................................................... 5-43, 5-108
specifications ................................................................................................... 2-9
typical wiring ................................................................................................... 3-17
ANSI CURVES
constants ......................................................................................................... 5-59
trip times ......................................................................................................... 5-59
AUTO-CONFIGURATION ................................................................................... 5-6
AUTOMATIC TRANSFORMATION .................................................................... 7-11
B
BLOCKING FROM LOGIC INPUTS ........................................................... 7-23, 7-24
BOOTWARE REVISION ..................................................................................... 6-21
C
CASE
description ........................................................................................................ 3-1
dimensions ....................................................................................................... 3-1
mounting ................................................................................................... 3-2, 3-3
CLOCK ............................................................................................................... 5-29
COMMISSIONING
conventions ...................................................................................................... 7-2
preliminary work ............................................................................................... 7-5
test equipment ................................................................................................. 7-3
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
I–I–I
INDEX
COMMUNICATIONS
DNP .................................................................................................................. 5-27
RS232 ............................................................................ 3-19, 3-20, 4-9, 4-13, 4-15
RS422 ..................................................................................................... 3-17, 3-19
RS485 ................................................................... 3-17, 3-18, 4-9, 4-10, 4-13, 4-15
setpoints ................................................................................................. 5-26, 5-27
wiring ........................................................................................................ 4-9, 4-10
CONDITIONS ...................................................................................................... 4-3
CONTROL POWER ..................................................................................... 2-5, 3-15
CT INPUTS ........................................................................................................ 3-12
CURRENT DEMAND
setpoints .......................................................................................................... 5-95
CURVES
definite time .................................................................................................... 5-59
FlexCurves™ .................................................................................................... 5-59
IAC ................................................................................................................... 5-61
IEC ................................................................................................................... 5-60
IEEE .................................................................................................................. 5-59
types ................................................................................................................ 5-58
D
DEFAULT MESSAGES ....................................................................................... 5-30
DEFINITE TIME CURVE ..................................................................................... 5-59
DEMAND METERING
setpoints .......................................................................................................... 5-41
DIELECTRIC STRENGTH TESTING ..................................................................... 7-6
DIFFERENTIAL
instantaneous differential ............................................................................... 5-57
percent differential .......................................................................................... 5-49
setpoints .......................................................................................................... 5-48
DIFFERENTIAL BLOCKED INDICATOR .............................................................. 4-3
DISPLAY .............................................................................................................. 4-2
DNP COMMUNICATIONS ................................................................................. 5-27
DRY CONTACT CONNECTIONS ....................................................................... 3-15
DYNAMIC CT RATIO MISMATCH ....................................................................... 5-6
E
ELEMENTS
introduction ..................................................................................................... 5-46
setpoints .......................................................................................................... 5-46
ENERGIZATION DETECTION SCHEME ............................................................ 7-22
ENERGIZATION INHIBIT .................................................................................. 5-53
ENERGY DATA CLEAR ...................................................................................... 6-16
ENERVISTA VIEWPOINT WITH THE 745 ......................................................... 4-40
ENTERING TEXT .................................................................................................. 4-5
EQUATIONS
definite time curve .......................................................................................... 5-59
FlexCurve™ ...................................................................................................... 5-59
EU DECLARATION OF CONFORMITY ............................................................... A-3
EVENT CAUSES ................................................................................................. 6-19
EVENT RECORDER
setup ................................................................................................................ 5-33
I–I–II
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
INDEX
F
FACTORY SERVICE ......................................................................................... 5-112
FAULT VALUES ............................................................................................... 5-110
FIFTH HARMONIC INHIBIT
setpoints .......................................................................................................... 5-56
FIFTH HARMONIC LEVEL
setpoints .......................................................................................................... 5-84
testing ............................................................................................................. 7-53
FIFTH HARMONIC RESTRAINT ........................................................................ 7-21
FIRMWARE, UPGRADING ................................................................................. 4-27
FLEXCURVES™
equation .......................................................................................................... 5-59
setpoints .......................................................................................................... 5-38
FLEXLOGIC™
example .............................................................................................. 5-101, 5-102
gates .............................................................................................................. 5-100
input types ..................................................................................................... 5-100
introduction ..................................................................................................... 5-99
output types .................................................................................................. 5-100
rules ............................................................................................................... 5-100
FREQUENCY
commissioning ........................................................................................ 7-43, 7-44
setpoints .......................................................................................................... 5-78
FREQUENCY DECAY
setpoints .......................................................................................................... 5-80
testing ............................................................................................................. 7-50
FRONT PANEL .................................................................................................... 4-1
FRONT PANEL PORT ........................................................................................ 3-19
G
GROUND INDICATOR ........................................................................................ 4-3
GROUND INSTANTANEOUS OVERCURRENT
setpoints .......................................................................................................... 5-71
specifications ................................................................................................... 2-7
testing .................................................................................................... 7-35, 7-36
GROUND OVERCURRENT SETPOINTS ............................................................ 5-69
GROUND TIME OVERCURRENT
setpoints .......................................................................................................... 5-70
specifications ................................................................................................... 2-7
testing ............................................................................................................. 7-32
H
HARDWARE REVISION ..................................................................................... 6-21
HARMONIC DERATING
correction ........................................................................................................ 5-64
setpoints .......................................................................................................... 5-89
testing ............................................................................................................. 7-57
HARMONIC INHIBIT ......................................................................................... 5-52
HARMONICS ............................................................................................ 5-38, 5-88
HI-POT TESTING ............................................................................................... 3-20
see DIELECTRIC STRENGTH TESTING
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
I–I–III
INDEX
HOTTEST-SPOT LIMIT
setpoints .......................................................................................................... 5-91
testing ............................................................................................................. 7-54
I
IAC CURVES
constants ......................................................................................................... 5-61
description ....................................................................................................... 5-61
trip times ......................................................................................................... 5-61
IEC CURVES
constants ......................................................................................................... 5-60
description ....................................................................................................... 5-60
trip times ......................................................................................................... 5-60
IED SETUP ......................................................................................................... 4-11
IEEE CURVES .................................................................................................... 5-59
IN SERVICE INDICATOR ..................................................................................... 4-2
INDICATORS
see LEDs and entries for individual indicators
INPUTS
AC voltage ....................................................................................................... 3-14
commissioning .................................................................................................. 7-9
specifications .................................................................................................... 2-5
INSERTION .......................................................................................................... 3-3
INSPECTION CHECKLIST ................................................................................... 1-1
INSTALLATION
electrical ............................................................................................................ 3-7
mechanical ........................................................................................................ 3-1
setpoints ................................................................................................... 1-9, 5-31
INSTANTANEOUS DIFFERENTIAL
setpoints .......................................................................................................... 5-57
specifications .................................................................................................... 2-6
testing ............................................................................................................. 7-23
INSULATION AGING
setpoints .......................................................................................................... 5-90
specifications .................................................................................................... 2-9
testing ............................................................................................................. 7-54
INVERSE CURVE 1 ............................................................................................ 5-85
IRIG-B ................................................................................................................ 3-20
K
KNEEPOINT ....................................................................................................... 7-20
L
LEDs
alarm ................................................................................................................. 4-3
description ......................................................................................................... 4-2
differential blocked ........................................................................................... 4-3
ground ............................................................................................................... 4-3
in logic diagrams ............................................................................................. 5-47
in service ........................................................................................................... 4-2
load-limit reduced ............................................................................................. 4-3
LOCAL ................................................................................................................ 4-3
I–I–IV
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
INDEX
message ...........................................................................................................
phase A .............................................................................................................
phase B .............................................................................................................
phase C .............................................................................................................
pickup ...............................................................................................................
self-test error ...................................................................................................
setpoint group 1 ...............................................................................................
system status ...................................................................................................
test mode .........................................................................................................
transformer de-energized ................................................................................
transformer overload .......................................................................................
trip ....................................................................................................................
4-3
4-3
4-3
4-3
4-3
4-2
4-3
4-3
4-2
4-3
4-3
4-3
INDICATOR ................................................................. 4-3
LOAD-LIMIT REDUCED
LOCAL INDICATOR ............................................................................................ 4-3
LOCAL RESET MODE ........................................................................................ 7-17
LOGIC ................................................................................................................ 5-47
LOGIC INPUTS .................................................................................................. 3-14
commissioning .................................................................................................. 7-7
setpoints .......................................................................................................... 5-44
specifications ................................................................................................... 2-6
wiring ............................................................................................................... 3-14
LOSS-OF-LIFE ................................................................................................... 5-90
LOSS-OF-LIFE LIMIT ............................................................................... 5-93, 7-55
M
MANEUVERING .................................................................................................. 1-3
MEASUREMENT UNITS .................................................................................... 5-47
MESSAGE INDICATOR ....................................................................................... 4-3
MINIMUM OPERATING CURRENT ................................................................... 7-57
MINIMUM PICKUP .......................................................................... 7-16, 7-23, 7-56
N
NAMEPLATE ....................................................................................................... 1-1
NEGATIVE SEQUENCE INSTANTANEOUS OVERCURRENT
setpoints .......................................................................................................... 5-77
specifications ................................................................................................... 2-7
testing ............................................................................................................. 7-42
NEGATIVE SEQUENCE OVERCURRENT .......................................................... 5-76
NEGATIVE SEQUENCE TIME OVERCURRENT
setpoints .......................................................................................................... 5-76
specifications ................................................................................................... 2-7
testing ............................................................................................................. 7-39
NEUTRAL INSTANTANEOUS OVERCURRENT
setpoints .......................................................................................................... 5-68
specifications ................................................................................................... 2-7
testing .................................................................................................... 7-31, 7-32
NEUTRAL OVERCURRENT ................................................................................ 5-66
NEUTRAL TIME OVERCURRENT
setpoints .......................................................................................................... 5-66
specifications ................................................................................................... 2-7
testing ............................................................................................................. 7-29
NUMERICAL SETPOINTS ................................................................................... 1-6
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
I–I–V
INDEX
O
ONLOAD TAP CHANGER .................................................................................. 5-37
OPERATING TIME ............................................................................................. 7-18
ORDER CODES .................................................................................................... 2-3
OUTPUT RELAYS
commissioning ........................................................................................... 7-7, 7-8
default FlexLogic™ ........................................................................................ 5-103
description ....................................................................................................... 3-16
setpoints ............................................................................................. 5-102, 5-107
specifications .................................................................................................... 2-9
typical wiring ................................................................................................... 3-16
OVERCURRENT
ground instantaneous ..................................................................................... 5-71
ground time ..................................................................................................... 5-70
negative sequence instantaneous .................................................................. 5-77
negative sequence time .................................................................................. 5-76
neutral instantaneous ..................................................................................... 5-68
neutral time ..................................................................................................... 5-66
phase ............................................................................................................... 5-58
OVERCURRENT CURVES
definite time .................................................................................................... 5-59
FlexCurves™ .................................................................................................... 5-59
IEEE .................................................................................................................. 5-59
OVEREXCITATION
5th harmonic level ........................................................................................... 5-84
description ....................................................................................................... 5-83
setpoints .......................................................................................................... 5-84
specifications .................................................................................................... 2-8
volts-per-hertz ................................................................................................. 5-85
OVERFREQUENCY
setpoints .......................................................................................................... 5-82
specifications .................................................................................................... 2-8
testing ............................................................................................................. 7-47
OVERVIEW .......................................................................................................... 2-1
P
PANEL CUTOUT .................................................................................................. 3-2
PASSCODE
changing ......................................................................................... 1-9, 1-10, 1-11
security ..................................................................................................... 1-9, 1-10
setpoints .......................................................................................................... 5-25
PERCENT DIFFERENTIAL
dual-slope characteristic ................................................................................ 5-50
harmonic restrained ........................................................................................ 7-16
operating principle .......................................................................................... 5-49
setpoints .......................................................................................................... 5-49
specifications .................................................................................................... 2-6
zones of protection ......................................................................................... 5-74
PHASE
PHASE
PHASE
PHASE
PHASE
A INDICATOR ......................................................................................... 4-3
ANGLE CORRECTION .......................................................................... 5-10
B INDICATOR ......................................................................................... 4-3
C INDICATOR ......................................................................................... 4-3
INSTANTANEOUS OVERCURRENT
setpoints .......................................................................................................... 5-65
I–I–VI
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
INDEX
specifications ................................................................................................... 2-7
testing .................................................................................................... 7-27, 7-28
PHASE OVERCURRENT .................................................................................... 5-58
PHASE SEQUENCE ........................................................................................... 3-12
PHASE SHIFTS
description ....................................................................................................... 5-24
table ................................................................................................................ 5-24
three-phase transformers ................................................................................ 5-8
PHASE TIME OVERCURRENT
setpoints .......................................................................................................... 5-63
specifications ................................................................................................... 2-7
testing ............................................................................................................. 7-25
PHASORS
ABC sequence ................................................................................................... 5-9
ACB sequence .................................................................................................. 5-10
PICKUP INDICATOR .......................................................................................... 4-3
PLACING THE RELAY INTO SERVICE .............................................................. 7-60
PREFAULT VALUES ......................................................................................... 5-110
PREFERENCES .................................................................................................. 5-25
PROTECTION SCHEMES
5th harmonic .......................................................................................... 5-84, 7-53
energization detection .................................................................................... 7-22
features ............................................................................................................ 2-2
frequency decay .............................................................................................. 5-80
frequency decay rate ...................................................................................... 7-50
ground instantaneous overcurrent ............................................... 5-71, 7-35, 7-36
ground time overcurrent ........................................................................ 5-70, 7-32
harmonic restrained percent differential ........................................................ 7-16
instantaneous differential ...................................................................... 5-57, 7-23
insulation aging ............................................................................................... 7-54
negative sequence instantaneous overcurrent ...................................... 5-77, 7-42
negative sequence time overcurrent ...................................................... 5-76, 7-39
neutral instantaneous overcurrent ............................................... 5-68, 7-31, 7-32
neutral time overcurrent ........................................................................ 5-66, 7-29
overfrequency ................................................................................................. 7-47
phase instantaneous overcurrent ................................................. 5-65, 7-27, 7-28
phase time overcurrent .......................................................................... 5-63, 7-25
restricted ground ............................................................................................. 5-72
restricted ground fault ........................................................................... 7-36, 7-38
specifications ................................................................................................... 2-6
THD level ................................................................................................. 5-88, 7-56
underfrequency ............................................................................. 5-79, 7-44, 7-47
volts-per-hertz ........................................................................................ 5-85, 7-52
R
REAR TERMINAL ASSIGNMENTS ...................................................................... 3-8
REAR TERMINAL LAYOUT ................................................................................. 3-7
REMOTE RESET MODE ..................................................................................... 7-18
RESETTING ........................................................................................................ 5-29
RESISTANCE GROUNDED WYE WINDING ...................................................... 5-73
RESTRICTED GROUND
implementation ............................................................................................... 5-74
setpoints .......................................................................................................... 5-72
settings example ............................................................................................. 5-74
testing .................................................................................................... 7-36, 7-38
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
I–I–VII
INDEX
zones of protection ......................................................................................... 5-74
RESTRICTED GROUND FAULT
specifications .................................................................................................... 2-7
RS232 COMMUNICATIONS
configuring with EnerVista 745 Setup .................................................... 4-13, 4-15
connections ....................................................................................................... 4-9
wiring ............................................................................................................... 3-19
RS422 COMMUNICATIONS .................................................................... 3-17, 3-19
RS485 COMMUNICATIONS ............................................................................. 3-18
configuring with EnerVista 745 Setup .................................................... 4-13, 4-15
connections .............................................................................................. 4-9, 4-10
wiring ............................................................................................................... 3-17
RTD
calibration ....................................................................................................... 7-13
driver/sensor ................................................................................................... 3-16
measured temperature ................................................................................... 7-13
resistance vs. temperature .............................................................................. 5-40
S
S1 745 SETUP ................................................................................................... 5-25
S2 SYSTEM SETUP ............................................................................................ 5-34
S3 LOGIC INPUTS ............................................................................................. 5-44
S4 ELEMENTS ................................................................................................... 5-46
S5 OUTPUTS ..................................................................................................... 5-99
S6 TESTING ..................................................................................................... 5-107
SCRATCHPAD ................................................................................................... 5-31
SECOND HARMONIC RESTRAINT ................................................................... 7-20
SELF-TEST ERROR INDICATOR ......................................................................... 4-2
SELF-TEST ERRORS .......................................................................................... 6-25
SERVICING ........................................................................................................ 7-60
SETPOINT ENTRY ........................................................................................ 4-5, 5-4
SETPOINT GROUP ............................................................................................ 5-47
SETPOINT GROUP 1 INDICATOR ...................................................................... 4-3
SETPOINT MESSAGE MAP ................................................................................. 5-1
SETPOINT WRITE ACCESS ................................................................................. 5-4
SETPOINTS
745 setup ......................................................................................................... 5-25
access jumper ................................................................................................... 1-6
changing ........................................................................................................... 1-6
elements .......................................................................................................... 5-46
entering with EnerVista 745 Setup software ................................................... 4-19
groups ............................................................................................................... 5-1
in logic diagrams ............................................................................................. 5-47
loading from a file ........................................................................................... 4-26
logic inputs ...................................................................................................... 5-44
messages .......................................................................................................... 5-1
numerical .......................................................................................................... 1-7
outputs ............................................................................................................ 5-99
saving to a file ................................................................................................. 4-27
system setup ................................................................................................... 5-34
testing ........................................................................................................... 5-107
text-based ......................................................................................................... 1-7
SIMULATION ................................................................................................... 5-108
SINGLE LINE DIAGRAM ..................................................................................... 2-3
SOFTWARE
I–I–VIII
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
INDEX
entering setpoints ........................................................................................... 4-19
hardware requirements .................................................................................... 4-8
installation ....................................................................................................... 4-10
loading setpoints ............................................................................................. 4-26
overview ........................................................................................................... 4-8
saving setpoints .............................................................................................. 4-27
serial communications ........................................................................... 4-13, 4-15
SOFTWARE REVISION ...................................................................................... 6-21
SOLID STATE OUTPUT TEST CIRCUIT ............................................................. 7-18
SOLID STATE TRIP OUTPUT ............................................................................. 3-17
SPECIFICATIONS ............................................................................................... 2-5
STATUS INDICATORS ........................................................................................ 4-2
SYSTEM STATUS INDICATORS ......................................................................... 4-3
T
TAP CHANGER FAILURE .................................................................................. 5-97
TAP MONITOR FAILURE ................................................................................... 7-55
TAP POSITION .................................................................................................. 7-15
TAP POSITION INPUT ................................................................................ 3-16, 5-8
TARGET MESSAGES .......................................................................................... 6-23
TEMPERATURE
ambient ......................................................................................... 5-39, 7-13, 7-14
operating ......................................................................................................... 2-10
RTD .................................................................................................................. 7-13
storage ............................................................................................................ 2-10
TEST MODE INDICATOR .................................................................................... 4-2
TEST SETUP ...................................................................................................... 7-25
TEXT SETPOINTS ............................................................................................... 1-7
THD LEVEL
setpoints .......................................................................................................... 5-88
testing ............................................................................................................. 7-56
TIME DELAYS .................................................................................................... 5-47
TIMERS ............................................................................................................ 5-106
TOC CURVES
IAC ................................................................................................................... 5-61
IEC ................................................................................................................... 5-60
TRACE MEMORY ............................................................................................. 5-105
TRANSFORMER ................................................................................................. 5-34
TRANSFORMER DE-ENERGIZED INDICATOR .................................................. 4-3
TRANSFORMER OVERLOAD .................................................................... 5-96, 7-58
TRANSFORMER OVERLOAD INDICATOR ......................................................... 4-3
TRANSFORMER POLARITY ............................................................................... 3-12
TRANSFORMER TYPES ..................................................................................... 5-13
TRANSFORMER-TYPE SELECTION .................................................................. 7-11
TRIP INDICATOR ................................................................................................ 4-3
TYPICAL WIRING DIAGRAM ............................................................................. 3-10
U
UNDERFREQUENCY
setpoints .......................................................................................................... 5-79
specifications ................................................................................................... 2-7
testing .................................................................................................... 7-44, 7-47
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
I–I–IX
INDEX
UNPACKING THE RELAY .................................................................................... 1-1
UPGRADE OPTIONS ......................................................................................... 5-31
UPGRADING FIRMWARE ................................................................................. 4-27
V
VIRTUAL INPUTS .............................................................................................. 5-45
VIRTUAL OUTPUTS ......................................................................................... 5-106
VOLTAGE INPUT ...................................................................................... 3-14, 5-39
commissioning ................................................................................................ 7-10
VOLTS-PER-HERTZ
setpoints .......................................................................................................... 5-85
testing ............................................................................................................. 7-52
W
WARRANTY ........................................................................................................ A-4
WEBSITE ............................................................................................................. 1-1
WET CONTACT CONNECTIONS ....................................................................... 3-15
WIRING DIAGRAM ............................................................................................ 3-10
WITHDRAWAL .................................................................................................... 3-3
WYE / DELTA TRANSFORMER ......................................................................... 5-10
Z
ZERO-SEQUENCE COMPONENT REMOVAL .......................................... 5-11, 7-12
ZERO-SEQUENCE CT INSTALLATION ............................................................. 3-14
I–I–X
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL